| Abbreviation | Definition |
|---|---|
| GRIM | GPS Receiver Interface Module |
| GRIT | Guard Recruits In Training |
| GRL | Global Reach Laydown |
| GRNT | Granted |
| GRODD | General Rittermann organized decisive defenses: |
| GROFAZ | GROeSSTE FELDHERN ALLE ZEIT = Greatest Field General of All Time |
| GROFAZ | GROsste Feldhern Alle Zeit |
| GRP | Glass Reinforced Plastic |
| Grp | Group |
| GRREG | GRaves REGistration |
| GRS | General Religious Support |
| GRSP | Ground Range Sustainment Program |
| GRT | Gear For Rugged Training |
| GRT | Gross Register Tonnage |
| GRUC | Greater Rome-Utica Chapter |
| Grunt | Foot Soldier in the Millitary |
| GRUNT | Government Reject Unfit For Naval Training |
| GRUNT | GRound Unit Not Trained |
| GRWSIM | Ground Warfare Simulation |
| GS | General Schedule |