| Orthopäde | orthopedist orthopaedist orthopaedic specialist orthopedic specialist orthopedic surgeon |
| Orthopädie | orthopaedics orthoorthopedicsaedics |
| Orthoepie | orthoepy |
| Orthopädin | orthopaedic specialist orthopaedist orthopedic specialist orthopedist |
| Arthropode | arthropod |
| Orthodoxie | Orthodoxy |
| Orthogon | rectangle |
| Orthoklas | orthoclase |
| Orthorexie | orthorexia |
| Orthese | orthosis orthotic |
| Orthofoto | orthophoto |
| Orthografie | orthography spelling |
| Orthoptist | orthoptist |
| Ortolan | ortolan |
| Ortsname | toponym place name placename |
| ortho- | ortho- |
| orthodox | orthodox |
| orthognath | orthognathic orthognathous |
| Arthropoda | arthropods |
| Kathode | cathode |