| Osterfest | Easter |
| Osterzeit | Easter |
| Opferfest | Eid al-Adha |
| rostfest | rustproof |
| Osterei | Easter egg |
| Osterfeuer | Easter fire |
| Osterhase | Easter Bunny |
| Otterfell | otter fur |
| Oktoberfest | Oktoberfest |
| Sommerfest | summer fair summer fête |
| feuerfest | fireproof |
| wasserfest | waterproof moisture proof water-resistant |
| ofenfest | ovenproof |
| ortsfest | sessile |
| Ostende | Ostend |
| Osterlamm | Paschal Lamb |
| Ostermond | April |
| Osteoklast | osteoclast |
| Osterferien | Easter holidays |
| Osteria | osteria |