| Adenoviridae | Adenoviridae |
| Adent | Slot and key |
| Adeos | Adaptive Domain Environment for Operating Systems |
| Adephaga | Adephaga |
| Adepta Sororitas | Sisters of Battle |
| adepte | supporter |
| adepte de la téléologie | teleologist |
| Adeptus Arbites | Adeptus Arbites |
| Adeptus Mechanicus | Adeptus Mechanicus |
| adessif | adessive case |
| Adeste Fideles | Adeste Fideles |
| Adewale Akinnuoye-Agbaje | Adewale Akinnuoye-Agbaje |
| adhan | adhan |
| Adhemar da Silva | Adhemar da Silva |
| Adherbal | Ad Herbal |
| Adhémar de Monteil | Adhemar of Le Puy |
| adhérence | adhesion |
| Adhérence roue-rail | Rail adhesion |
| adhérent | follower |
| adhérente | follower |
| Adhérents | Party members |
| adhérer | connect |
