| Abbreviation | Definition |
|---|---|
| ARL | The Association Of Research Libraries |
| ARLA | Association of Residential Letting Agents (UK) |
| ARMA | American Radio Manufacturers Association |
| ARMA | Asphalt Roofing Manufacturers Association |
| ARMS | Awareness, Revenue, Members, and Synergy |
| ARNEC | Asia-Pacific Regional Network for Early Childhood |
| ARO | Association for Research in Otolaryngology |
| ARPFNB | Association of Registered Professional Foresters of New Brunswick |
| ARPG | Asphalt Rubber Producers Group |
| ARRA | Asphalt Recycling & Reclaiming Association |
| ARRS | Association Of Road Racing Statisticians |
| ARRT | American Registry of Radiologic Technologists |
| ARS | Association Registered Ship |
| ARSC | Association Of Reciprocal Safety Councils |
| ArSHA | Arizona Speech-Language-Hearing Association |
| ARTA | Association of Retail Travel Agents |
| ARWA | Arizona Rural Water Association |
| ARZA | Association Of Reform Zionists Of America |
| ASA | American Society of Anesthesiologists |
| ASA | American Society of Anesthesiology |