| Aktivismus | activism |
| Aktionismus | actionism |
| Nativismus | nativism |
| Atavismus | atavism |
| Aktualismus | actualism |
| Aktivist | activist |
| Aktivistin | activist |
| Antivirus | antivirus |
| Putinismus | Putinism |
| Akmeismus | Acmeism |
| Albinismus | albinism |
| Alpinismus | alpinism |
| Altruismus | altruism |
| Animismus | animism |
| Asterismus | asterism |
| Atheismus | atheism |
| Autismus | autism |
| Latinismus | latinism |
| Optimismus | optimism |
| Aktivieren | activation |
| aktivieren | activate |