USSR
| Acronym | Definition |
|---|---|
| USSR | Union of Soviet Socialist Republics (now Commonwealth of Independent States) |
| USSR | Uninterrupted Sustained Silent Reading (education) |
| USSR | Underground Security Systems Research |
| USSR | Universal Solid State Relay |
| USSR | United Soldiers of Soldat Realistic (gaming clan) |
| USSR | Unstimulated Salivary Secretion Rate |