| Octavius | Octavius |
| Octavian | Octavian |
| Octan | octane |
| Atavismus | atavism |
| Oktave | octave octonion Cayley algebra Cayley numbers |
| Gravis | grave accent grave |
| Antonius | Antonius |
| Arcadius | Arcadius |
| Arius | Arius |
| Ascanius | Ascanius |
| Atilius | Atilius |
| Darius | Darius |
| Aktuarius | actuary |
| Blasius | Blaise Blase Blaze |
| Celsius | Celsius |
| Claudius | Claude |
| Hilarius | Hilary Ellery |
| Marius | Marius |
| Radius | radius |
| Vltava | Vltava |