| orthognath | orthognathic orthognathous |
| Orthognathie | orthognathy orthognathysm |
| orthogonal | orthogonal |
| Orthogon | rectangle |
| Orthoklas | orthoclase |
| Orthofoto | orthophoto |
| Orthografie | orthography spelling |
| Orthographie | orthography spelling |
| Orthopäde | orthopedist orthopaedist orthopaedic specialist orthopedic specialist orthopedic surgeon |
| Mythograph | mythographer |
| Orthodoxie | Orthodoxy |
| Orthonitrat | orthonitrate |
| Orthorexie | orthorexia |
| orthogonalität | orthogonality |
| Kortholt | kortholt |
| Ortgang | bargeboard gableboard verge vergeboard |
| Orthoepie | orthoepy |
| Orthoptist | orthoptist |
| Orthopädie | orthopaedics orthoorthopedicsaedics |
| Orthopädin | orthopaedic specialist orthopaedist orthopedic specialist orthopedist |