| Atomradius | radius |
| Atomrakete | nuclear missile |
| Autoradio | car radio automobile radio |
| Radius | radius |
| Arcadius | Arcadius |
| Athanasius | Athanasius |
| Atomkraft | nuclear energy |
| Atomkrieg | nuclear war |
| Atommacht | nuclear power |
| Atommasse | atomic mass |
| Atommine | atomic demoliton munition |
| Atommodell | atom model atomic model |
| Atompilz | mushroom cloud |
| Atomreaktor | nuclear reactor |
| Atomwaffe | nuclear weapon atomic weapon |
| Atomzeit | atomic time |
| atomar | atomic |
| Ptomain | ptomaine |
| Automatik | automatism automatic automatic transmission |
| Automation | automation |