| Orthofoto | orthophoto |
| Orthogon | rectangle |
| orthodox | orthodox |
| Orthodoxie | Orthodoxy |
| Orthoklas | orthoclase |
| Kortholt | kortholt |
| Orthoepie | orthoepy |
| Orthopäde | orthopedist orthopaedist orthopaedic specialist orthopedic specialist orthopedic surgeon |
| ortho- | ortho- |
| orthognath | orthognathic orthognathous |
| orthogonal | orthogonal |
| Oxhoft | hogshead |
| Orthonitrat | orthonitrate |
| Orthorexie | orthorexia |
| ortsfest | sessile |
| unorthodox | licentious |
| Anorthosit | anorthosite |
| Drehort | location |
| Fortluft | exhaust air outgoing air |
| Orthese | orthosis orthotic |