| orthodox | orthodox |
| Orthodoxie | Orthodoxy |
| Orthogon | rectangle |
| unorthodox | licentious |
| Orthoepie | orthoepy |
| Orthofoto | orthophoto |
| ortho- | ortho- |
| Rhodos | Rhodes |
| Orthoklas | orthoclase |
| Orthorexie | orthorexia |
| orthodoxer Jude | Orthodox Jew |
| Kortholt | kortholt |
| Orthese | orthosis orthotic |
| Orthopäde | orthopedist orthopaedist orthopaedic specialist orthopedic specialist orthopedic surgeon |
| Orthopädie | orthopaedics orthoorthopedicsaedics |
| Orthopädin | orthopaedic specialist orthopaedist orthopedic specialist orthopedist |
| Ortolan | ortolan |
| orthogonal | orthogonal |
| Method | Methodius |
| Kathode | cathode |