| Ontogenie | ontogeny |
| Ontogenese | ontogenesis ontogeny |
| Ontologie | ontology |
| Neotenie | neoteny |
| Osteopenie | osteopenia |
| Oniomanie | oniomania |
| Ontologe | ontologist |
| Ontologin | ontologist |
| Röntgenium | roentgenium |
| Roentgenium | roentgenium |
| Röntgen | X-ray |
| röntgen | X-ray |
| Untoten | undead |
| Antonia | Antonette Latonya |
| Antonymie | antonymy |
| Autogamie | autogamy |
| Oktogon | octagon |
| autogen | autogenous |
| fotogen | photogenic |
| Osteogenese | osteogenesis |