| Oktogon | octagon |
| Oktagon | octagon |
| Oktonion | octonion |
| Orthogon | rectangle |
| Doktorin | Doctor |
| Oktober | October |
| Oktole | octuplet |
| Oktopus | octopus |
| Togo | Togo |
| Togoer | Togolese |
| autogen | autogenous |
| fotogen | photogenic |
| Dogon | Dogon |
| Oregon | Oregon |
| Tigon | tiglon tigon |
| Doktorat | doctorate |
| Oktal- | octal |
| Oktant | Octans |
| Oktillion | octillion quindecillion |
| Doktor | doctor physican |