| Acronym | Definition |
|---|
| URR | Urea Reduction Ratio (urinary dialysis laboratory data) |
| URR | Ultima Ratio Regum |
| URR | Upstream Regulatory Region (human papillomavirus) |
| URR | Underground Railroad |
| URR | Ultimate Recoverable Reserves (natural resources) |
| URR | Ultimately Recoverable Resources (oil reserves) |
| URR | Union Railroad Company |
| URR | Unconstrained Requirements Report |
| URR | Unscheduled Removal Rate |
| URR | Ultra Reliable Radar |
| URR | Ugly Radio Rebellion (band) |
| URR | Unit Readiness Report |
| URR | Unexpired Risk Reserve |
| URR | Unpaid Return Rate |
| URR | Upper Hatch Rail Retracted Auxiliary |
| URR | UN Roulement Regiment (UK military) |
| URR | Ultra-Reliable Router |
| URR | Utilities External Review (board) |
| URR | Unresourced Requirement |
| URR | User Readiness Review |