| Abbreviation | Definition |
|---|---|
| AAS | aneurysm of atrial septum |
| AAS | Ann Arbor Staging |
| AAS | aortic arch syndrome |
| AAS | Associate Applied Science |
| AAS | atlantoaxial subluxation |
| AAS | atomic absorption spectophotometry |
| AAS | Australian Association of Surgeons |
| AAST | American Association for Surgery of Trauma |
| ABC | aberrant behaviour checklist |
| ABC | absolute blast count |
| ABC | absolute bone conduction |
| ABC | acalculous biliary colic |
| ABC | acid-based control |
| ABC | airway, breathing and circulation |
| ABC | alternative birth centre |
| ABC | aneurysmal bone cyst |
| ABC | antibody-binding capacity |
| ABC | apnoea, bradycardia, cyanosis |
| ABC | ATP-binding cassette transporter |
| ABC | avidin-biotin complex immunoperoxidase |