| Onkologie | oncology |
| Onkologin | oncologist |
| Onkologe | oncologist |
| Ökologie | ecology |
| Ontologie | ontology |
| Önologie | oenology enology |
| Arkologie | arcology |
| Ökologin | ecologist |
| Mykologie | mycology |
| Tokologie | tocology |
| Ökologe | ecologist |
| Indologie | Indology |
| Ontologe | ontologist |
| Ontologin | ontologist |
| Oologie | oology |
| Pönologie | penology |
| Önologin | oenologist |
| Noologie | noology |
| Oktologie | octology |
| Otologie | otology |