| Ökologie | ecology |
| Ökologin | ecologist |
| Tokologie | tocology |
| Ökologe | ecologist |
| Onkologie | oncology |
| Oologie | oology |
| Oktologie | octology |
| Otologie | otology |
| Önologie | oenology enology |
| Ökonomie | economy |
| Arkologie | arcology |
| Onkologin | oncologist |
| Kolonie | colony |
| Mykologie | mycology |
| Onkologe | oncologist |
| -ologie | -ology |
| Aerologie | aerology |
| Horologie | horology |
| Pönologie | penology |
| Ufologie | ufology |