| Oligopol | oligopoly |
| Oligopolist | oligopolist |
| oligozän | Oligocene |
| Oligozän | Oligocene |
| Oligomer | oligomer |
| Olivenöl | olive oil |
| oligopolistisch | oligopolistic |
| oligotroph | oligotrophic |
| Oligarch | oligarch |
| Oligurie | oliguria |
| ölig | oily |
| Obligo | commitment |
| Sligo | Sligo |
| trigonal | trigonal |
| Gigolo | gigolo |
| epigonal | epigon |
| rigoros | rigorous savagely |
| Göpel | horse-gin |
| Duopol | duopoly |
| Dyopol | duopoly |