| Abbreviation | Definition |
|---|---|
| SIL | System Integration Laboratory |
| SILS | Standard for Inter-operable LAN Security |
| SIM | stand for In Military |
| SIM | System Impact Message |
| SIMA | Systems Integration Management Activity |
| SIMAIN | Simulated Automatic Digital Network Input |
| SIMAIN | SIMulated Automatic INput |
| SIMAN | Simulations Manager |
| SIMAOUT | Simulated Automatic Digital Network Output |
| SIMBAD | Standoff Instride Mine Breaching Agent Device |
| SIMBAD | Standoff Instride Mine Breaching Device |
| SIME | Security Intelligence Middle East |
| SIMITAR | Simulation In Training for Advanced Readiness |
| SIMLM | Single Integrated Medical Logistics Management |
| SIMLM | Single Integrated Medical Logistics Manager |
| SIMM | Single In-line Memory Module |
| SIMNET | Simulation Network |
| SIMNET-T | Simulation Network Trainer |
| SIMS | Smart Integrated Monitoring System |
| SIMS-X | Selected Item Management System-Expanded |