| Abbreviation | Definition |
|---|---|
| UCI | Updated Coordinating Instructions |
| UCI | User- Computer Interface |
| UCK | Ushtria Clirimtare e Kosoves (Kosovo Liberation Army) |
| UCL | Unit Concentrated Load |
| UCLA | University of California, Los Angeles |
| UCLASS | Unmanned Carrier-Launched Airborne Surveillance and Strike |
| UCMJ | The Uniform Code Of Military Justice |
| UCMJ | Uniform Code Of Military Justice |
| UCOFT | Unit Conduct of Fire Trainer |
| UCP | Ultimate Combat Pistol |
| UCP | Unified Command Plan |
| UCP | Universal Camouflage Pattern |
| UCR | Unsatisfactory Condition Report |
| UCS | Universal Multiple-Octet Coded Character Set |
| UCSR | Unit Control Supply Rate |
| UCT | Underwater Construction Team |
| UCT | User Check Test |
| UCW | Unlawful Carrying Weapons |
| UCX | Unemployment Compensation for Ex-Servicemembers |
| UD | Unit Defense |