Definition from Wiktionary, the free dictionary
- Acoustical Society of America
- American Standards Association, which has changed its name to American National Standards Institute (ANSI).
- American Society for Anesthesiology.
- All Sciences Association.
- Amateur Swimming Association.
- (organic chemistry, medicine) acetylsalicylic acid (aspirin)
- (military) Air Sovereignty Alert. Refers to fighter jet units that provide aerial defense of the nation via high-readiness aircraft.
- (Britain) Advertising Standards Authority.