| Abbreviation | Definition |
|---|---|
| FBCB2 | Force XXI Battle Command - Brigade and Below |
| FBD | Fight Before Dishonor |
| FBDO | Flying Branch Duty Officer |
| FBE | Fort Belvoir Engineering |
| FBED | Fort Belvoir Engineering Directorate |
| FBEFO | Fort Belvoir Engineering Field Office |
| FBEO | Fort Belvoir Engineering Office |
| FBI | Female Body Inspector |
| FBIM | Fire Brigade Intervention Model |
| FBL | Future Battle Laboratory |
| FBM | Fleet Ballistic Missile |
| FBO | Faith-Based Organization |
| FBO | Fixed Base Operation |
| FBOIPFD | Final Basis of Issue Plan Feeder Data |
| FBR | Fouled-up Beyond Repair |
| FBS | Fast Beam Search |
| FBS | Fighter Bomber Squadron |
| FBS | Finance Battlefield System |
| FBS | FUBAR, But Stable |
| FC | Field Circular |