| Abbreviation | Definition |
|---|---|
| GAMP | Guided Antiarmor Mortar Projectile |
| GAMSS | Global Air Mobility Support System |
| GANG | Georgia Army National Guard |
| GAO | General Accounting Office |
| GAP | Geographic Analysis Project |
| GAP | Geographic Approach to Planning |
| GAP | Glock Automatic Pistol |
| GAP | Go Away Pakis |
| GAP | Gross Aggregate Position |
| GAP | Group Advisory Panel |
| GAPEWS | Graphic Air Picture Early Warning System |
| GAR | Gateway Access Request |
| GAR | Grand Army of the Republic |
| GARS | Global Area Reference System |
| GAT | Gatling Gun |
| GAT | Government Acceptance Test |
| GAT | Governmental Assistance Team |
| GAT | Green Army Toy |
| GAT | Guidance, Apportionment, and Targeting |
| GATA | Global Anti-terrorism Assistance |