| Abbreviation | Definition |
|---|---|
| GBNI | Girls Brigade NI |
| GBNI | Girls Brigade Northern Ireland |
| GBPH | German's Bombed Pearl Harbour |
| GBR | Ground-Based Radar |
| GBRS | Ground-Based Radar System |
| GBR-T | Ground-Based Radar Terminal |
| GBS | Generic Battle System |
| GBS | George Barton Shick |
| GBS | Global Broadcast Service |
| GBS | Global Broadcast System |
| GBS | Global Broadcasting System |
| GBS | Ground-Based Sensor |
| GBS/CGS | Ground-Based Sensor Common Ground Station |
| GBU | Glide Bomb Unit |
| GBU | Guided Bomb Unit |
| GBU-8/BHOBOS | Glide Bomb Unit 8, Homing Bomb System |
| GBYM | Gandhi Brigade Youth Media |
| GC | Gaining Command |
| GC | Gas Chromatography |
| GC | Geneva Convention |