| osculation | osculación |
| Ose | Monosacárido |
| Osechi | Osechi |
| oseille | pasta |
| Oseille sauvage | Oxalis |
| Osella | Osella |
| Oseltamivir | Oseltamivir |
| oser | arriesgarse |
| oser se dire | llamarse a sí mismo |
| Osgiliath | Osgiliath |
| Oshare Kei | Oshare Kei |
| Oshawa | Oshawa |
| Oshikoto | Oshikoto |
| osier | mimbre |
| osier fleuri | laurel de San Antonio |
| Osijek | Osijek |
| Osirak | Osirak |
| Osiris | Osiris |
| Oskar Camenzind | Oscar Camenzind |
| Oskar Hertwig | Oscar Hertwig |
| Oskar Kokoschka | Oskar Kokoschka |
| Oskar Lafontaine | Oskar Lafontaine |
| Oskar Morgenstern | Oskar Morgenstern |
| Oskar Panizza | Oskar Panizza |
| Oskar Schindler | Oskar Schindler |
| Oslo | Oslo |
| Oslo T-Bane | Metro de Oslo |
| Osman I er | Osman I |
| Osman Ier | Osmán I |
| Osman II | Osman II |
| Osman III | Osman III |
| Osmaniye | Provincia de Osmaniye |
| Osmanli | Osmanlíes |
| osmium | osmio |
| Osmo Vänskä | Osmo Vänskä |
| Osmonde royale | Osmunda regalis |
| Osmorégulation | Osmorregulación |
| osmose | ósmosis |
| osmose inverse | osmosis inversa |
| osmotique | osmótico |
| Osmotrophe | Osmotrofia |
| Osmunda | Osmunda |
| Osmundaceae | Osmundaceae |
| Osnabrück | Osnabrück |
| Osogna | Osogna |
| Osorkon | Osorkon III |
| Osorkon Ier | Osorkon I |
| Osorkon II | Osorkon II |
| Osorkon III | Osorkon III |
| Osorkon IV | Osorkon IV |
| Osorno | Osorno |
| Osque | Osco |
| Osroène | Osroene |
| ossature | armazón |
| Ossement | Hueso |
| osseux | delgado |
| Ossian | Ossian |
| ossification | osificación |
| Ossip Mandelstam | Osip Mandelstam |
| Ossip Zadkine | Ossip Zadkine |
| Osso buco | Ossobuco |
| Osso-buco | Carne en salsa con su hueso |
| Ossuaire de Sedlec | Osario de Sedlec |
| Ossètes | Osetia |
| Ossétie | Osetia |
| Ossétie du Sud | Osetia del Sur |
| Ossétie-du-Nord-Alanie | Osetia del Norte - Alania |
| Ossétie-du-Sud | Osetia del Sur |
| Ostalgie | Ostalgie |
| Osteichthyes | Osteichthyes |
| Ostende | Ostende |
| ostensiblement | en un modo llamativo |
| ostensoir | custodia |
| ostentation | ostentación |
| Osteoglossiformes | Osteoglossiformes |
| Ostermundigen | Ostermundigen |
| Osterode am Harz | Distrito de Osterode am Harz |
| Ostholstein | Distrito de Ostholstein |
| Ostpolitik | Ostpolitik |
| Ostraciidae | Boxeo |
| Ostracode | Ostracoda |
| Ostracoderme | Ostracodermos |
| Ostracon | Ostracon |
| Ostrava | Ostrava |
| Ostrea edulis | Ostreidae |
| Ostrogoths | Pueblo ostrogodo |
| Ostrov | Isla |
| ostréiculture | ostricultura |
| Ostwald | Ostwald |
| Ostéichthyens | Osteichthyes |
| Ostéoblaste | Osteoblasto |
| Ostéogenèse imparfaite | Osteogénesis imperfecta |
| Ostéologie | Osteología |
| ostéopathe | osteópata |
