| Autonarr | piston head pistonhead |
| Autocar | bus |
| Autobahn | motorway freeway highway interstate highway |
| Autodafé | auto-da-fé |
| Autofahrer | motorist driver car driver |
| Autofahrt | car ride |
| Autofähre | car ferry |
| Autogiro | autogyro autogiro |
| Autohaus | car dealer car dealership |
| Autokauf | car purchase |
| Automarke | car brand make of car |
| Automarkt | car mart |
| Automat | vending machine |
| Autor | author literator |
| Autosave | autosave |
| autark | autarkic self-sufficient self-sustaining |
| autogam | autogamous |
| autonom | autonomous self-governed |
| Durtonart | major key |
| atonal | atonal |