| Owa | Owa |
| Oware | Oware |
| Owari Province | Provincia de Owari |
| owe | deber |
| owe someone an explanation | deber una explicación |
| owed | a pagar |
| Owen Arthur | Owen Arthur |
| Owen Barfield | Owen Barfield |
| Owen Chamberlain | Owen Chamberlain |
| Owen Willans Richardson | Owen Willans Richardson |
| Owen Wilson | Owen Wilson |
| Owerpass | Puente de mando |
| owing | deudor |
| owing to | debido a |
| owing to someone | pendiente |
| owl | búho |
| Owl Nebula | Nebulosa del Búho |
| owlet | mochuelo |
| Owlet-nightjar | Aegothelidae |
| owlish | de búho |
| own | conceder |
| Own capital | Capital social |
| Own resources | Recursos propios |
| owner | propietario |
| owner name | nombre del propietario |
| owner of a shipping company | armador |
| owner's guide | guía del usuario |
| ownership | propiedad |
| Ownership equity | Capital social |
| ox | novillo |
| Ox heart | Bos taurus |
| Ox tongue | Bos taurus |
| Oxalidaceae | Oxalidaceae |
| Oxalidales | Oxalidales |
| Oxaliplatin | Oxaliplatino |
| Oxalis acetosella | Oxalis |
| Oxalis stricta | Oxalis stricta |
| Oxandrolone | Oxandrolona |
| Oxapampa Province | Provincia de Oxapampa |
| oxeye | margarita |
| oxeye daisy | margarita |
| Oxfam | Oxfam |
| Oxford | Oxford |
| Oxford English Dictionary | Oxford English Dictionary |
| Oxford Franciscan school | Escuela Franciscana de Oxford |
| Oxford Movement | Movimiento de Oxford |
| Oxford Street | Oxford Street |
| Oxford University Handball Club | Oxford University Handball Club |
| Oxfordian stage | Oxford |
| Oxfordshire | Oxfordshire |
| Oxhide | Bos taurus |
| oxidation | oxidación |
| Oxidation state | Estado de oxidación |
| oxidation-reduction | oxidación-reducción |
| oxide | óxido |
| oxidisable material | material oxidable |
| oxidising agent | agente oxidante |
| oxidize | oxidar |
| Oxley Wild Rivers National Park | Parque Nacional Ríos Salvajes de Oxley |
| Oxoacid | Ácido oxácido |
| Oxonium ion | Hidronio |
| oxtail | rabo de buey |
| Oxus | Amu Daria |
| Oxy-fuel welding and cutting | Soldadura a gas |
| Oxyacetylene burner | Soplete oxiacetilénico |
| Oxyartes | Oxiartes |
| Oxyathres of Persia | Oxatres de Persia |
| Oxybeles | Oxibeles |
| Oxycodone | Oxicodona |
| Oxydizing | Oxidante |
| oxygen | oxígeno |
| Oxygen burning | Fusión del oxígeno |
| oxygen content | contenido de oxígeno |
| Oxygen cycle | Ciclo del oxígeno |
| Oxygen cylinder | Oxígeno |
| oxygen mask | máscara de oxígeno |
| Oxygen tank | Tubo de oxígeno |
| oxygen tent | cámara de oxígeno |
| oxygenate | oxigenar |
| oxygenated | oxidado |
| oxygenation | oxigenación |
| Oxygene | Oxígeno |
| Oxymonad | Oxymonadida |
