| Abbreviation | Definition |
|---|---|
| ACF | Army Cadet Forces |
| ACF | Auto- Correlation Function |
| ACFA | Army Cadet Force Association |
| ACFMS | Airframe Cumulative Fatigue Monitoring System |
| ACFP | Army Congressional Fellowship Program |
| ACFS | Advanced Concept Flight Simulator |
| ACFT | Aircraft |
| ACFT | Army Cadet Fitness Test |
| ACG | All Conditions Gear |
| ACG | Assistant Chaplain General |
| ACH | ACCS Common Hardware |
| ACH | Advanced Combat Helmet |
| ACHN | Army Community Health Nursing |
| ACHV | Achieve |
| ACI | Allocated Configuration Item |
| ACI | Army Counter-Intelligence |
| ACI | Assign Call Inhibit |
| ACI | Aviazione Cobelligerante Italiana(Italian Co-Belligerent Air Force) |
| ACIC | Aeronautical Chart and Information Center |
| ACIC | Army Counterintelligence Center |