| AAA | amateur athletic association (skr.) |
|---|---|
| AAN | American Academy of Neurology (skr.) |
| AAU | Amateur Athletic Union (skr.) |
| ABB | Amateur Boat Building |
| ABN | Association of British Neurologists |
| ABORIGINOVIA | Indoeurópania |
| AC | amateur club (skr.), amatérsky klub (angl.skr.) |
| ADOLAR | postava z Weberovej opery Euryanta |
| ADRIA | európsky ropovod |
| ADRIAN | anglický lekár, neurofyziológ (Edgar Douglas, 1889-1977) |