| Abbreviation | Definition |
|---|---|
| ARTEMIS | Project Management Software System |
| ARTH | Academy for Reiki Training and Healing |
| ARTIC | A Real-time Interface Coprocessor |
| ARTIST | Assessment Resource Tools to Improve Statistical Thinking |
| ARTR | Almost Ready To Run |
| ARTS | Automatic Range Transponder System |
| ARTS | Automated Resource Tracking System |
| ARTS | At Risk Talented Students |
| ARTS | Arts Restoration Throughout Schools |
| ARTS | Analog Real-Time Synthesizer |
| ARTS | Automated Radar Terminal System |
| ARTS | Automated Remote Tracking Station |
| ARU | Australian Rugby Union |
| ARU | Arthritis Rehabilitation Unit |
| ARUPS | Angle-resolved Ultra-violet Photoemission Spectroscopy |
| ARV | Anti- RetroViral |
| ARV | Average Relative Variance |
| ARV | American Rottweiler Verein |
| ARV | Armed Response Vehicle |
| ARV | Acquired Immunodeficiency Syndrome-related Virus |
| ARV | Adelaide River Virus |
| ARV | Average Retail Value |
| ARV | Approximate Retail Value |
| ARWL | Akademia Rolnicza W. Lublinie |
| ARWO | Aerial Reconnaissance Weather |
| ARXPS | Angle Resolved X-ray Photoemission Spectroscopy |
| AS | Associate of Science |
| AS | Arsenic |
| AS | Ammonium Sulphate |
| AS | Autonomous System |
| AS | Add Sideways |
| AS | Anal sphincter |
| AS | Auris Sinistra (left Ear) |
| AS | Arteriosclerosis |
| AS | Astigmatism |
| AS | Aortic Stenosis |
| AS | Ankylosing Spondylitis |
| AS | Asperger Syndrome |
| AS | Advanced Solutions |
| AS | Active Screensaver |
| AS | Auricle Sinistrus |
| AS | Acidified Serum |
| ASA | Alkenyl Succinic Anhydride |
| ASA | Aperture Setting Adjustment |
| ASA | Apparent Strength of Adhesion |
| ASA | AcetylSalicylic Acid (Aspirin) |
| ASA | Accredited Senior Appraiser |
| ASA | Assistant Secretary of the Army |
| ASA | Associate of the Society of Actuaries |
| ASA | Alarm Systems Agent |