| Abbreviation | Definition |
|---|---|
| AB | AirBorne |
| AB | All Battle |
| AB | Answer Back |
| AB | Artificer Branch |
| AB | Atomic Bomb |
| AB2 | Army Brigade and Below |
| ABA | Adjusted Basic Allotment |
| ABACUS | Air Battle Analysis Center Utility System |
| ABAIT | Automatic Board Assembly, Inspection, and Test |
| ABAN | Aviation Boatswain's Mate Airman Striker |
| ABAT | AirLand Battle Advanced Technologies |
| ABC | Advanced Blade Concept |
| ABC | Airborne Corps |
| ABC | All Blocks Covered |
| ABC | American, British, and Canadian |
| ABC | Army Battle Command |
| ABC | Asian Brown Cloud |
| ABC | Atomic Bacterial Chemical |
| ABC | Atomic, Biological, Chemical |
| ABC | Australian Broadcasting Commision |