| Acronym | Definition |
| U | wind speed |
| U/C | unit cost; upconverter |
| UA | unmanned aircraft |
| UAOBS | upper air observation |
| UAR | unconventional assisted recovery |
| UARCC | unconventional assisted recovery coordination cell |
| UAS | unmanned aircraft system |
| UCFF | Unit Type Code Consumption Factors File |
| UCMJ | Uniform Code of Military Justice |
| UCP | Unified Command Plan |
| UCT | underwater construction team |
| UDAC | unauthorized disclosure analysis center |
| UDC | unit descriptor code |
| UDESC | unit description |
| UDL | unit designation list |
| UDP | unit deployment program |
| UDT | underwater demolition team |
| UE | unit equipment |
| UFC | Unified Facilities Criteria |
| UFO | ultrahigh frequency follow-on |
| UFR | unfunded requirement |
| UGA | ungoverned area |
| UGIRH | Urban Generic Information Requirements Handbook |
| UGM-84A | Harpoon |
| UGM-96A | Trident I |
| UHF | ultrahigh frequency |
| UHV | Upper Huallaga Valley |
| UIC | unit identification code |
| UICIO | unit identification code information officer |
| UIRV | unique interswitch rekeying variable |
| UIS | unit identification system |
| UJTL | Universal Joint Task List |
| UK | United Kingdom |
| UK(I) | United Kingdom and Ireland |
| ULC | unit level code |
| ULF | ultra low frequency |
| ULLS | unit level logistics system |
| ULN | unit line number |
| UMCC | unit movement control center |
| UMCM | underwater mine countermeasures |
| UMD | unit manning document; unit movement data |
| UMIB | urgent marine information broadcast |
| UMMIPS | uniform material movement and issue priority system |
| UMO | unit movement officer |
| UMPR | unit manpower personnel record |
| UMT | unit ministry team |
| UN | United Nations |
| UN-DMT | United Nations disaster management team |
| unaccounted for | (DOD) An inclusive term (not a casualty status) applicable to personnel whose person or remains are not recovered or otherwise accounted for following hostile action. Commonly used when referring to personnel who are killed in action and whose bodies are not recovered. See also casualty; casualty category; casualty status; casualty type. |
| UNAMIR | United Nations Assistance Mission in Rwanda |
| unanticipated target | (DOD) A target of opportunity that was unknown or not expected to exist in the operational environment. See also target of opportunity. See also operational area; target; target of opportunity. |
| unauthorized commitment | (DOD) An agreement that is not binding solely because the United States Government representative who made it lacked the authority to enter into that agreement on behalf of the Unites States Government. See also ratification. |
| UNC | United Nations Command |
| uncertain environment | (DOD) Operational environment in which host government forces, whether opposed to or receptive to operations that a unit intends to conduct, do not have totally effective control of the territory and population in the intended operational area. |
| uncharged demolition target | (DOD,NATO) A demolition target for which charges have been calculated, prepared, and stored in a safe place, and for which execution procedures have been established. See also demolition target. |
| unclassified matter | (DOD,NATO) Official matter which does not require the application of security safeguards, but the disclosure of which may be subject to control for other reasons. See also classified matter. |
| UNCLOS | United Nations Convention on the Law of the Sea |
| unconventional assisted recovery | (DOD) Nonconventional assisted recovery conducted by special operations forces. Also called UAR. See also authenticate; evader; recovery. |
| unconventional assisted recovery coordination cell | (DOD) A compartmented special operations forces facility, established by the joint force special operations component commander, staffed on a continuous basis by supervisory personnel and tactical planners to coordinate, synchronize, and de-conflict nonconventional assisted recovery operations within the operational area assigned to the joint force commander. Also called UARCC. See also joint operations center; joint personnel recovery center; special operations forces; unconventional assisted recovery. |
| unconventional assisted recovery mechanism | (DOD) A recovery mechanism developed and managed by special operations forces. Also called UARM. See also recovery; unconventional assisted recovery. |
| unconventional assisted recovery team | (DOD) A designated special operations forces unconventional warfare ground or maritime force capable of conducting unconventional assisted recovery with indigenous or surrogate forces. Also called UART. |
| unconventional warfare | (DOD) A broad spectrum of military and paramilitary operations, normally of long duration, predominantly conducted through, with, or by indigenous or surrogate forces who are organized, trained, equipped, supported, and directed in varying degrees by an external source. It includes, but is not limited to, guerrilla warfare, subversion, sabotage, intelligence activities, and unconventional assisted recovery. Also called UW. |
| UNCTAD | United Nations Conference on Trade and Development |
| UND | urgency of need designator |
| UNDAC | United Nations disaster assessment and coordination |
| undersea warfare | (DOD) Operations conducted to establish and maintain control of the underwater environment by denying an opposing force the effective use of underwater systems and weapons. It includes offensive and defensive submarine, antisubmarine, and mine warfare operations. Also called USW. See also antisubmarine warfare; mine warfare. |
| underwater demolition | (DOD,NATO) The destruction or neutralization of underwater obstacles; this is normally accomplished by underwater demolition teams. |
| underwater demolition team | (DOD) A group of officers and enlisted specially trained and equipped for making hydrographic reconnaissance of approaches to prospective landing beaches; for effecting demolition of obstacles and clearing mines in certain areas; locating, improving, and marking of useable channels; channel and harbor clearance; acquisition of pertinent data during pre-assault operations, including military information; observing the hinterland to gain information useful to the landing force; and for performing miscellaneous underwater and surface tasks within their capabilities. Also called UDT. |
| underway replenishment | (DOD,NATO) See replenishment at sea. |
| underway replenishment force | (DOD,NATO) A task force of fleet auxiliaries (consisting of oilers, ammunition ships, stores issue ships, etc.) adequately protected by escorts furnished by the responsible operational commander. The function of this force is to provide underway logistic support for naval forces. See also force. |
| underway replenishment group | (DOD) A task group configured to provide logistic replenishment of ships underway by transfer-at-sea methods. |
| UNDHA | United Nations Department of Humanitarian Affairs |
| UNDP | United Nations development programme |
| UNDPKO | United Nations Department for Peacekeeping Operations |
| UNEF | United Nations emergency force |
| UNEP | United Nations environment program |
| UNESCO | United Nations Educational, Scientific, and Cultural Organization |
| unexploded explosive ordnance | (DOD) Explosive ordnance which has been primed, fused, armed or otherwise prepared for action, and which has been fired, dropped, launched, projected, or placed in such a manner as to constitute a hazard to operations, installations, personnel, or material and remains unexploded either by malfunction or design or for any other cause. Also called UXO. See also explosive ordnance. |
| UNHCHR | United Nations High Commissioner for Human Rights |
| UNHCR | United Nations Office of the High Commissioner for Refugees |
| UNICEF | United Nations Children's Fund |
| unified action | (DOD) The synchronization, coordination, and/or integration of the activities of governmental and nongovernmental entities with military operations to achieve unity of effort. |
| unified combatant command | (DOD) See unified command. |
| unified command | (DOD) A command with a broad continuing mission under a single commander and composed of significant assigned components of two or more Military Departments that is established and so designated by the President, through the Secretary of Defense with the advice and assistance of the Chairman of the Joint Chiefs of Staff. Also called unified combatant command. See also combatant command; subordinate unified command. |
| Unified Command Plan | (DOD) The document, approved by the President, that sets forth basic guidance to all unified combatant commanders; establishes their missions, responsibilities, and force structure; delineates the general geographical area of responsibility for geographic combatant commanders; and specifies functional responsibilities for functional combatant commanders. Also called UCP. See also combatant command; combatant commander. |
| UNIFIL | United Nations Interim Force in Lebanon |
| uniformed services | (DOD) The Army, Navy, Air Force, Marine Corps, Coast Guard, National Oceanic and Atmospheric Administration, and Public Health Services. See also Military Department; Military Service. |
| UNIL | unclassified national information library |
| unit | (DOD) 1. Any military element whose structure is prescribed by competent authority, such as a table of organization and equipment; specifically, part of an organization. |
| unit | (DOD) 2. An organization title of a subdivision of a group in a task force. |
| unit | (DOD) 3. A standard or basic quantity into which an item of supply is divided, issued, or used. In this meaning, also called unit of issue. |
| unit | (DOD) 4. With regard to Reserve Components of the Armed Forces, denotes a Selected Reserve unit organized, equipped, and trained for mobilization to serve on active duty as a unit or to augment or be augmented by another unit. Headquarters and support functions without wartime missions are not considered units. |
| unit aircraft | (DOD) Those aircraft provided an aircraft unit for the performance of a flying mission. |
| unit commitment status | (DOD,NATO) The degree of commitment of any unit designated and categorized as a force allocated to NATO. |
| unit designation list | (DOD) A list of actual units by unit identification code designated to fulfill requirements of a force list. |
| unit identification code | (DOD) A six-character, alphanumeric code that uniquely identifies each Active, Reserve, and National Guard unit of the Armed Forces. Also called UIC. |
| unit line number | (DOD) A seven-character alphanumeric code that describes a unique increment of a unit deployment, i.e., advance party, main body, equipment by sea and air, reception team, or trail party, in a Joint Operation Planning and Execution System time-phased force and deployment data. Also called ULN. |
| unit loading | (DOD,NATO) The loading of troop units with their equipment and supplies in the same vessels, aircraft, or land vehicles. See also loading. |
| unit movement control center | (DOD) A temporary organization activated by major subordinate commands and subordinate units during deployment to control and manage marshalling and movement. Also called UMCC. See also deployment; marshaling; unit. |
| unit movement data | (DOD) A unit equipment and/or supply listing containing corresponding transportability data. Tailored unit movement data has been modified to reflect a specific movement requirement. Also called UMD. |
| unit of issue | (DOD) In its special storage meaning, refers to the quantity of an item; as each number, dozen, gallon, pair, pound, ream, set, yard. Usually termed unit of issue to distinguish from "unit price." See also unit. |
| unit personnel and tonnage table | (DOD) A table included in the loading plan of a combat-loaded ship as a recapitulation of totals of personnel and cargo by type, listing cubic measurements and weight. Also called UP&TT. |
| unit readiness | (DOD) See readiness. |
| unit type code | (DOD) A Joint Chiefs of Staff developed and assigned code, consisting of five characters that uniquely identify a "type unit." |
| UNITAF | unified task force |
| UNITAR | United Nations Institute for Training and Research |
| United States | (DOD) Includes the land area, internal waters, territorial sea, and airspace of the United States, including the following: a. US territories, possessions, and commonwealths; and b. Other areas over which the US Government has complete jurisdiction and control or has exclusive authority or defense responsibility. |
| United States Armed Forces | (DOD) Used to denote collectively only the regular components of the Army, Navy, Air Force, Marine Corps, and Coast Guard. See also Armed Forces of the United States. |
| United States controlled shipping | (DOD) That shipping under US flag and selected ships under foreign flag considered to be under "effective US control," i.e., that can reasonably be expected to be made available to the United States in time of national emergency. See also effective US controlled ships. |
| United States message text format | (DOD) A program designed to enhance joint and combined combat effectiveness through standardization of message formats, data elements, and information exchange procedures. Standard message formats with standard information content provides all tactical commanders at the joint interface with a common playing field and a common language. Also called USMTF. |
| United States Naval Ship | (DOD) A public vessel of the United States that is in the custody of the Navy and is: a. Operated by the Military Sealift Command and manned by a civil service crew; or b. Operated by a commercial company under contract to the Military Sealift Command and manned by a merchant marine crew. Also called USNS. See also Military Sealift Command. |
| United States Signals Intelligence System | (DOD) The unified organization of signals intelligence activities under the direction of the Director, National Security Agency/Chief, Central Security Service. It consists of the National Security Agency/Central Security Service, the components of the Military Services authorized to conduct signals intelligence, and such other entities (other than the Federal Bureau of Investigation) authorized by the National Security Council or the Secretary of Defense to conduct signals intelligence activities. Also called USSS. See also counterintelligence. |
| United States Transportation Command | (DOD) The unified command with the mission to provide strategic air, land, and sea transportation and common-user port management for the Department of Defense across the range of military operations. Also called USTRANSCOM. See also global transportation network; single port manager; transportation component command; unified command. |
| unitized load | (DOD) A single item or a number of items packaged, packed, or arranged in a specified manner and capable of being handled as a unit. Unitization may be accomplished by placing the item or items in a container or by banding them securely together. See also palletized unit load. |
| UNITREP | unit status and identity report |
| unity of effort | (DOD) Coordination and cooperation toward common objectives, even if the participants are not necessarily part of the same command or organization - the product of successful unified action. |
| Universal Joint Task List | (DOD) A menu of capabilities (mission-derived tasks with associated conditions and standards, i.e., the tools) that may be selected by a joint force commander to accomplish the assigned mission. Once identified as essential to mission accomplishment, the tasks are reflected within the command joint mission essential task list. Also called UJTL. |
| universal polar stereographic grid | (DOD) A military grid prescribed for joint use in operations in limited areas and used for operations requiring precise position reporting. It covers areas between the 80 degree parallels and the poles. |
| Universal Postal Union | (DOD) A worldwide postal organization to which the United States and most other countries are members. The exchange of mail, except parcel post, between the United States and other nations is governed by the provisions of the Universal Postal Union convention. Also called UPU. |
| Universal Time | (DOD) A measure of time that conforms, within a close approximation, to the mean diurnal rotation of the Earth and serves as the basis of civil timekeeping. Universal Time (UT1) is determined from observations of the stars, radio sources, and also from ranging observations of the moon and artificial Earth satellites. The scale determined directly from such observations is designated Universal Time Observed (UTO); it is slightly dependent on the place of observation. When UTO is corrected for the shift in longitude of the observing station caused by polar motion, the time scale UT1 is obtained. When an accuracy better than one second is not required, Universal Time can be used to mean Coordinated Universal Time. Also called ZULU time. Formerly called Greenwich Mean Time. |
| universal transverse mercator grid | (DOD,NATO) A grid coordinate system based on the transverse mercator projection, applied to maps of the Earth's surface extending to 84 degrees N and 80 degrees S latitudes. Also called UTM grid. |
| UNJLC | United Nations Joint Logistic Centre |
| unknown | (DOD) 2. An unidentified target. An aircraft or ship that has not been determined to be hostile, friendly, or neutral using identification friend or foe and other techniques, but that must be tracked by air defense or naval engagement systems. |
| unknown | (DOD) 1. A code meaning "information not available." |
| unknown | (DOD) 3. An identity applied to an evaluated track that has not been identified. See also assumed friend; friend; hostile; neutral; suspect. |
| UNLOC | United Nations logistic course |
| unmanned aircraft | (DOD) An aircraft or balloon that does not carry a human operator and is capable of flight under remote control or autonomous programming. Also called UA. |
| unmanned aircraft system | (DOD) That system whose components include the necessary equipment, network, and personnel to control an unmanned aircraft. Also called UAS. |
| UNMIH | United Nations Mission in Haiti |
| UNMILPOC | United Nations military police course |
| UNMOC | United Naitons military observers course |
| UNMOVCC | United Nations movement control course |
| UNO | unit number |
| UNOCHA | United Nations Office for the Coordination of Humanitarian Affairs |
| UNODC | United Nations Office on Drugs and Crime |
| UNODIR | unless otherwise directed |
| UNOSOM | United Nations Operations in Somalia |
| UNPA | United Nations Participation Act |
| unplanned target | (DOD) A target of opportunity that is known to exist in the operational environment. See also operational area; target; target of opportunity. |
| UNPROFOR | United Nations protection force |
| UNREP | underway replenishment |
| UNREP CONSOL | underway replenishment consolidation |
| UNRWA | United Nations Relief and Works Agency for Palestine Refugees in the Near East |
| UNSC | United Nations Security Council |
| unscheduled convoy phase | (DOD,NATO) The period in the early days of war when convoys are instituted on an ad hoc basis before the introduction of convoy schedules in the regular convoy phase. |
| UNSCR | United Nations Security Council resolution |
| UNSG | United Nations Secretary-General |
| UNSOC | United Nations staff officers course |
| unstable patient | (DOD) A patient whose physiological status is in fluctuation. Emergent, treatment and/or surgical intervention are anticipated during the evacuation. An unstable patient's rapidly changing status and requirements are beyond the standard en route care capability and requires medical/surgical augmentation. |
| unstuffing | (DOD) The removal of cargo from a container. Also called stripping. |
| UNTAC | United Nations Transition Authority in Cambodia |
| UNTSO | United Nations Truce and Supervision Organization |
| UNV | United Nations volunteer |
| unwanted cargo | (DOD,NATO) A cargo loaded in peacetime which is not required by the consignee country in wartime. |
| unwarned exposed | (DOD,NATO) The vulnerability of friendly forces to nuclear weapon effects. In this condition, personnel are assumed to be standing in the open at burst time, but have dropped to a prone position by the time the blast wave arrives. They are expected to have areas of bare skin exposed to direct thermal radiation, and some personnel may suffer dazzle. See also warned exposed; warned protected. |
| UOF | use of force |
| UP&TT | unit personnel and tonnage table |
| UPU | Universal Postal Union |
| urban triad | (DOD) The three elements that compose the urban environment: complex man-made physical terrain, a population of significant size and density, and an infrastructure. See also infrastructure; joint urban operations. |
| URDB | user requirements database |
| urgent mining | (DOD,NATO) In naval mine warfare, the laying of mines with correct spacing but not in the ordered or planned positions. The mines may be laid either inside or outside the allowed area in such positions that they will hamper the movements of the enemy more than those of our own forces. |
| US commercial assets | (DOD) US commercial aircraft, spacecraft, flag shipping, offshore, and land-based assets located landward of the outer limit of the continental shelf of the United States, its territories, and possessions, and excluding those privately owned oil rigs operating under foreign license in disputed offshore areas. |
| US Defense Representative | (DOD) A senior US officer in a foreign country representing the Secretary of Defense, the Chairman of the Joint Chiefs of Staff, and the commander of the unified command that coordinates the security matters regarding in-country, non-combat Department of Defense (DOD) elements (i.e., DOD personnel and organizations under the command of a combatant commander but not assigned to, or attached to, the combatant commander). Also called USDR. |
| US forces | (DOD) All Armed Forces (including the Coast Guard) of the United States, any person in the Armed Forces of the United States, and all equipment of any description that either belongs to the US Armed Forces or is being used (including Type I and II Military Sealift Command vessels), escorted, or conveyed by the US Armed Forces. |
| US national | (DOD) US citizen and US permanent and temporary legal resident aliens. |
| US person | (DOD) For intelligence purposes, a US person is defined as one of the following: (1) a US citizen; (2) an alien known by the intelligence agency concerned to be a permanent resident alien; (3) an unincorporated association substantially composed of US citizens or permanent resident aliens; or (4) a corporation incorporated in the United States, except for those directed and controlled by a foreign government or governments. |
| US Transportation Command coordinating instructions | (DOD) Instructions of the US Transportation Command that establish suspense dates for selected members of the joint planning and execution community to complete updates to the operation plan database. Instructions will ensure that the target date movement requirements will be validated and available for scheduling. |
| USA | United States Army |
| USAB | United States Army barracks |
| USACCSA | United States Army Command and Control Support Agency |
| USACE | United States Army Corps of Engineers |
| USACFSC | United States Army Community and Family Support Center |
| USACHPPM | US Army Center for Health Promotion and Preventive Medicine |
| USACIDC | United States Army Criminal Investigation Command |
| USAF | United States Air Force |
| USAFE | United States Air Forces in Europe |
| USAFEP | United States Air Force, Europe pamphlet |
| USAFLANT | United States Air Force, Atlantic Command |
| USAFR | United States Air Force Reserve |
| USAFRICOM | United States Africa Command |
| USAFSOC | United States Air Force, Special Operations Command |
| USAFSOF | United States Air Force, Special Operations Forces |
| USAFSOS | USAF Special Operations School |
| USAID | United States Agency for International Development |
| USAITAC | United States Army Intelligence Threat Analysis Center |
| USAJFKSWC | United States Army John F. Kennedy Special Warfare Center |
| USAMC | United States Army Materiel Command |
| USAMMA | United States Army Medical Materiel Agency |
| USAMPS | United States Army Military Police School |
| USAMRICD | US Army Medical Research Institute for Chemical Defense |
| USAMRIID | US Army Medical Research Institute of Infectious Diseases |
| USAMRMC | US Army Medical Research and Materiel Command |
| USANCA | United States Army Nuclear and Combating Weapons of Mass Destruction Agency |
| USAO | United States Attorney Office |
| USAR | United States Army Reserve |
| USARCENT | United States Army, Central Command |
| USAREUR | United States Army, European Command |
| USARIEM | United States Army Research Institute of Environmental Medicine |
| USARJ | United States Army, Japan |
| USARNORTH | US Army Forces North |
| USARPAC | United States Army, Pacific Command |
| USARSO | United States Army, Southern Command |
| USASOC | United States Army Special Operations Command |
| USB | upper side band |
| USBP | United States Border Patrol |
| USC | United States Code; universal service contract |
| USCENTAF | United States Central Command Air Forces |
| USCENTCOM | United States Central Command |
| USCG | United States Coast Guard |
| USCGR | United States Coast Guard Reserve |
| USCIS | US Citizenship and Immigration Services |
| USCS | United States Cryptologic System; United States Customs Service |
| USCYBERCOM | United States Cyber Command |
| USD(A&T) | Under Secretary of Defense for Acquisition and Technology |
| USD(AT&L) | Under Secretary of Defense for Acquisition, Technology, and Logistics |
| USD(C) | Under Secretary of Defense (Comptroller) |
| USD(I) | Under Secretary of Defense for Intelligence |
| USD(P&R) | Under Secretary of Defense for Personnel and Readiness |
| USD(P) | Under Secretary of Defense for Policy |
| USD(R&E) | Under Secretary of Defense for Research and Engineering |
| USDA | United States Department of Agriculture |
| USDAO | United States defense attache office |
| USDELMC | United States Delegation to the NATO Military Committee |
| USDR | United States defense representative |
| use of force policy | (DOD) Policy guidance issued by the Commandant, US Coast Guard, on the use of force and weapons. |
| USELEMCMOC | United States Element Cheyenne Mountain Operations Center |
| USELEMNORAD | United States Element, North American Aerospace Defense Command |
| USERID | user identification |
| USERRA | Uniformed Services Employment and Reemployment Rights Act |
| USEUCOM | United States European Command |
| USFJ | United States Forces, Japan |
| USFK | United States Forces, Korea |
| USFORAZORES | United States Forces, Azores |
| USFS | United States Forest Service |
| USFWS | United States Fish and Wildlife Service |
| USG | United States Government |
| USGS | United States Geological Survey |
| USIA | United States Information Agency |
| USIC | United States interdiction coordinator |
| USIS | United States Information Service |
| USJFCOM | United States Joint Forces Command |
| USLANTFLT | United States Atlantic Fleet |
| USLO | United States liaison officer |
| USMARFORCENT | United States Marine Component, Central Command |
| USMARFORLANT | United States Marine Component, Atlantic Command |
| USMARFORPAC | United States Marine Component, Pacific Command |
| USMARFORSOUTH | United States Marine Component, Southern Command |
| USMC | United States Marine Corps |
| USMCEB | United States Military Communications-Electronics Board |
| USMCR | United States Marine Corps Reserve |
| USMER | United States merchant ship vessel locator reporting system |
| USMILGP | United States military group |
| USMILREP | United States military representative |
| USMOG-W | United States Military Observer Group - Washington |
| USMS | United States Marshals Service |
| USMTF | United States message text format |
| USMTM | United States military training mission |
| USN | United States Navy |
| USNAVCENT | United States Naval Forces, Central Command |
| USNAVEUR | United States Naval Forces, Europe |
| USNAVSO | US Naval Forces Southern Command |
| USNCB | United States National Central Bureau (INTERPOL) |
| USNMR | United States National Military representative |
| USNMTG | United States North Atlantic Treaty Organization (NATO) Military Terminology Group |
| USNO | United States Naval Observatory |
| USNORTHCOM | United States Northern Command |
| USNR | United States Navy Reserve |
| USNS | United States Naval Ship |
| USPACAF | United States Air Forces, Pacific Command |
| USPACFLT | United States Pacific Fleet |
| USPACOM | United States Pacific Command |
| USPFO(P&C) | United States Property and Fiscal Office (Purchasing and Contracting) |
| USPHS | United States Public Health Service |
| USPS | United States Postal Service |
| USREPMC | United States representative to the military committee (NATO) |
| USSOCOM | United States Special Operations Command |
| USSOUTHAF | United States Air Force, Southern Command |
| USSOUTHCOM | United States Southern Command |
| USSS | United States Secret Service (TREAS); United States Signals Intelligence (SIGINT) System |
| USSTRATCOM | United States Strategic Command |
| USTRANSCOM | United States Transportation Command |
| USUN | United States Mission to the United Nations |
| USW | under sea warfare |
| USW/USWC | undersea warfare and/or undersea warfare commander |
| USYG | Under Secretary General |
| UT1 | unit trainer; Universal Time |
| UTC | Coordinated Universal Time; unit type code |
| UTM | universal transverse mercator |
| UTO | unit table of organization |
| UTR | underwater tracking range |
| UUV | unmanned underwater vehicle |
| UVEPROM | ultraviolet erasable programmable read-only memory |
| UW | unconventional warfare |
| UWOA | unconventional warfare operating area |
| UXO | unexploded explosive ordnance; unexploded ordnance |
