| acétate | acetate |
| Acétate de benzyle | Benzyl acetate |
| Acétate de calcium | Calcium acetate |
| Acétate de vinyle | Vinyl acetate |
| acétimètre | acetimeter |
| acétique | acetic |
| acétomètre | acetometer |
| acétone | acetone |
| Acétonémie | Acetonaemia |
| acétoselle | wood-sorrel |
| acétyl | acetyl |
| Acétyl-coenzyme A | Acetyl-CoA |
| Acétylcholine | Acetylcholine |
| acétylène | acetylene |
| AD | AD |
| AD Carmelita | Asociación Deportiva Carmelita |
| Ad Dawhah | Ad Dawhah |
| ad hoc | ad hoc |
| Ad hominem | Ad hominem |
| Ad maiorem Dei gloriam | Ad maiorem Dei gloriam |
| AD Municipal Liberia | Municipal Liberia |
| AD Municipal Pérez Zeledon | Municipal Pérez Zeledón |
| ad nauseam | ad nauseam |
| AD Ramonense | Asociación Deportiva Ramonense |
| AD San Carlos | Asociacion Deportiva San Carlos |
| Ad-Aware | Ad-Aware |
| Ad-Dakhla | Dakhla Oasis |
| Ad-hoc On-demand Distance Vector | Ad-hoc On-demand Distance Vector |
| Ada | Ada |
| Ada Air | Ada Air |
| Ada Ciganlija | Ada Ciganlija |
| Ada de Carie | Ada of Caria |
| Ada Kaleh | Ada Kaleh |
| Ada Lovelace | Ada Lovelace |
| Ada Velipojë | KS Ada Velipojë |
| ADAC | ADAC |
| Adad | Adad |
| Adad-Idri | Hadadezer |
| Adad-nerari Ier | Adad-nirari I |
| Adad-Nerari III | Adad-nirari III |
| Adad-Nirari II | Adad-nirari II |
| adage | aphorism |
| adagio | adagio |
