| original | archetypal |
| Original Amiga chipset | Amiga Original chipset |
| Original Design Manufacturer | Original design manufacturer |
| Original Dixieland Jass Band | Original Dixieland Jass Band |
| Original Video Animation | Original video animation |
| originale | crank |
| originalité | quaintness |
| origine | parentage |
| Origine de la philosophie | Ancient philosophy |
| Origine de qqch | Root |
| Origine de réplication | Origin of replication |
| Origine des etoiles | Star origin |
| Origine des étoiles | Star origin |
| Origine du peuple roumain | Origin of Romanians |
| originel | original |
| originellement | originally |
| Origines de la guerre de Sécession | Origins of the American Civil War |
| Origines de la vie | Origin of life |
| Origlio | Origlio |
| Origène | Origen |
| Orihuela CF | Orihuela CF |
| Orio Mastropiero | Orio Mastropiero |
| Orioles de Baltimore | Baltimore Orioles |
| Orion | Orion |
| Orion Pictures Corporation | Orion Pictures |
| Orishas | Orisha |
| Orissa | Orissa |
| Oristano | Oristano |
| Orithye | Oreithyia |
| Orjen | Orjen |
| Orjout | Orjout |
| Orkhon | Orkhon River |
| Orkneyinga saga | Orkneyinga saga |
| Orks | Ork |
| Orkut | Orkut |
| ORL | ENT |
| Orlandina Basket | Orlandina Basket |
| Orlando | Orlando |
| Orlando Bloom | Orlando Bloom |
| Orlando furioso | Orlando furioso |
| Orlando Mohorovic | Orlando Mohorovic |
| Orlando Peçanha | Orlando Peçanha de Carvalho |
| Orlando Pirates Football Club | Orlando Pirates FC |
| Orlea | Orlea |
| Orloff | Orlov |
| Orlovat | Orlovat |
| Orly | Orly |
| Orléanais | Orléanais |
| Orléanisme | Orléanist |
| Orléans | Orleans |
| Orlík | Orlík |
| Ormaiztegi | Ormaiztegi |
| Ormalingen | Ormalingen |
| orme | elm |
| Orme champêtre | Field Elm |
| orme de Sibérie | Siberian elm |
| ormeau | abalone |
| Ormen Lange | Ormen Lange |
| Ormey | Ulmiz |
| Orminge | Orminge |
| Ormont-Dessous | Ormont-Dessous |
| Ormont-Dessus | Ormont-Dessus |
| Ormož | Ormož |
| Ormurin langi | Ormurin Langi |
| Ornaisons | Ornaisons |
| Ornans | Ornans |
| Ornella Muti | Ornella Muti |
| ornement | ornament |
| ornemental | decorative |
