| Oxydation | oxidation |
| Oxidation | oxidation |
| oxyton | oxytone |
| Oxygenation | oxygenation |
| Foundation | foundation |
| Prädation | predation |
| Nidation | nidation |
| Oration | collect |
| Operation | surgery operation |
| Ovation | ovation |
| Ovulation | ovulation |
| Oxymoron | oxymoron |
| Oxytocin | oxytocin |
| Oxytonon | oxytone |
| Lapidation | lapidation |
| Autoxidation | autoxidation |
| Emendation | emendation |
| Inundation | flood |
| Laudatio | eulogy encomium laudation laudatory speech panegyric |
| Soldatin | soldier |