| Abbreviation | Definition |
|---|---|
| AR | Attack And Release |
| AR | Augustus Rex |
| AR | Authorization Required |
| AR | Auto Regression |
| AR | Average Reference |
| AR | The Alter Real |
| AR | The Artificial Radionuclide |
| ARA | A Absolute Rowing Anarchy |
| ARA | Active Racist Attacking |
| ARA | Actively Racist Attacking |
| ARA | Administration and Regulatory Affairs |
| ARA | Administrative Request Acknowledge |
| ARA | Administrative Review Action |
| ARA | Aggregate Risk Analysis |
| ARA | AMD Really Awesome |
| ARA | American Recovery Association |
| ARA | American Renal Associates |
| ARA | American Rental Association |
| ARA | American Rimfire Association |
| ARA | Amsterdam Rotterdam and Antwerp |