| oligotroph | oligotrophic |
| Oligarch | oligarch |
| Oligopol | oligopoly |
| Allotrop | allotrope |
| allotrop | allotropic |
| Heliotrop | heliotrope |
| anisotrop | anisotropic |
| neurotroph | neurotrophic |
| autotroph | autotroph |
| auxotroph | auxotrophic |
| isotrop | isotropic |
| oligozän | Oligocene |
| Oligozän | Oligocene |
| Oligomer | oligomer |
| Oligurie | oliguria |
| Obligation | bond obligation |
| rigoros | rigorous savagely |
| Logotyp | logotype |
| ostgotisch | Ostrogothic |
| Egotrip | ego trip |