| Abbreviation | Definition |
|---|---|
| EROS | Earth Resources Observation System |
| EROS | Eliminate Range Zero Situation (spelled with either letter 'o' Or Digit Zero) |
| ERP | Enroute Reporting Point |
| ERP | Enterprise Resource Planning |
| ERP | Equipment Reception Party |
| ER-PGM | Extended Range Precision Guided Munition |
| ERPS | Equipment Release Priority System |
| ERR | Engineering Research Report |
| ERRO | Emergency Response and Recovery Office |
| ERS | Electronics Rack System |
| ERS | Ellipsoidal Reflector Spotlight |
| ERSD | Estimated Return to Service Date |
| ERT | Emergency Response Team (FEMA) |
| ERT | Engineer Reconnaissance Team |
| ERT | Execution Reference Time |
| ERT-A | Emergency Response Team - Advance Element |
| ERTF | Enlisted Retention Task Force |
| ERU | Emergency Response Unit |
| ERW | Empower Rune Weapon |
| ERW | Enhanced Radiation Weapon |