| Abbreviation | Definition |
|---|---|
| AQEC | Aerospace Qualified Electronic Component |
| AQEC | Aerospace Qualified Electronic Components |
| AQEC | Aerospace Qualified Electronics Components |
| AQI | ACCESS Query Interface |
| AR | Aspect Ratio |
| AR | Audio Rate |
| ARC | Anti-Reflective Coating |
| ARDE | Aspect-Ratio-Dependent Etching |
| ARE | Activated Reactive Evaporation |
| AREC | American River Electric Company |
| ARECU | Alabama Rural Electric Credit Union |
| ARES | Alternative Retail Electric Supplier |
| ARF | Audio Receiver File |
| ARIA | Advanced Research In Audio |
| ARIEL | Artificial Robotic Intelligent Electronic Life |
| ARIMA | Auto Regressive Integrated Moving Average |
| ARINC | Aeronautical Radio Incorporated |
| ARM | Anti-Radiation Missile |
| ARM | Audio Rate Modulation |
| ARMS | Ampere Root Mean Square |