| orthotrope Platte | orthotropic deck |
| Orthodoxe Kirche | Orthodox Church |
| orthodoxe Kirche | Orthodox Church |
| Orthodoxe Kirchen | Eastern Orthodox Church |
| Orthorexie | orthorexia |
| Orthosalpetersäure | orthonitric acid |
| orthodoxer Jude | Orthodox Jew |
| orthogonalität | orthogonality |
| Orthografie | orthography spelling |
| Orthographie | orthography spelling |
| Orthopäde | orthopedist orthopaedist orthopaedic specialist orthopedic specialist orthopedic surgeon |
| Orthopädie | orthopaedics orthoorthopedicsaedics |
| Arthropathie | arthropathy |
| Arthroplastik | arthroplasty |
| Hotplate | hotplate |
| Ohrtrompete | Eustachian tube |
| Anthropophagie | anthropophagy |
| der Rote Platz | Red Square |
| tektonische Platte | tectonic plate |
| Roter Platz | Red Square |