| singular | único |
| singularity | peculiaridad |
| singularly | extremamente |
| singulative | singulativo |
| Sinhalese | cingalés |
| Sinhalese language | Idioma cingalés |
| sinicization | sinización |
| sinicize | achinar |
| sinister | siniestro |
| Sinister Six | Seis Siniestros |
| sinisterness | aspecto siniestro |
| Sinitic | sinítico |
| Siniša Mihajlović | Siniša Mihajlović |
| sink | bajar |
| sink hole | cenote |
| sink in | dejar una profunda huella |
| sink into oblivion | ser totalmente olvidado |
| Sink trap | Sifon |
| Sink-hole | Cueva |
| sinker | plomo |
| sinking | hundimiento |
| Sinking funds | Fondo común de inversión |
| Sinking of Prince of Wales and Repulse | Hundimiento del HMS Prince of Wales y del HMS Repulse |
| sinless | puro |
| Sinn Féin | Sinn Féin |
| sinner | pecador |
| Sinningia | Sinningia |
| Sinnoh | Sinnoh |
| Sino- | chino- |
| Sino-French War | Guerra Franco-China |
| Sino-Japanese War | Guerra Sino-Japonesa |
| Sino-Soviet border conflict | Conflicto de la frontera chino-soviética |
| Sino-Soviet split | Ruptura Sino-Soviética |
| Sino-Tibetan languages | Lenguas sino-tibetanas |
| sinologist | sinólogo |
| sinology | sinología |
| Sinon | Sinón |
| Sinop | Sinop |
| Sinop Province | Provincia de Sinop |
| Sinope | Sinop |
| Sinophobia | sinofobia |
| Sinophone | sinófono |
| Sinornithosaurus | Sinornithosaurus |
| Sinosauropteryx | Sinosauropteryx |
| Sinosaurus | Sinosaurus |
| Sinotherium | Sinotherium |
| SINPO | SINPO |
| Sinraptor | Sinraptor |
| Sinraptoridae | Sinraptoridae |
| Sint Eustatius | Sint Eustatius |
| Sint Maarten | Isla de San Martín |
| Sint Maarten national football team | Selección de fútbol de Sint Maarten |
| Sint-Agatha-Berchem | Berchem-Sainte-Agathe |
| Sint-Jans-Molenbeek | Molenbeek-Saint-Jean |
| Sint-Katelijne-Waver | Sint Katelijne Waver |
| Sint-Laureins | Saint-Laurent |
| Sint-Niklaas | Fiesta de San Nicolás |
| sinter | sinterizar |
| sintering | sinterización |
| Sinterklaas | Fiesta de San Nicolás |
| Sinthome | Sinthome |
| Sintra | Sintra |
| Sintra National Palace | Palacio Nacional de Sintra |
| sinuate | festoneado |
| sinuosity | sinuosidad |
| sinuous | sinuoso |
| sinus | seno |
| sinusitis | sinusitis |
| sinusoidal | senoidal |
| Sinú River | Río Sinú |
| SIO maser | Máser SIO |
| Siobhán Donaghy | Siobhán Donaghy |
| Sion | Sion |
| Siona people | Siona |
| Siouan | Siux |
| Siouan languages | Lenguas siouan |
| Siouan-Catawban languages | Lenguas sioux |
| Sioux | Siux |
| Sioux language | Idioma dakhota-lakhota |
| sip | tomar |
| Sipahi | Sipahi |
| Sipaliwini District | Sipaliwini |
| Sipe | Lamela |
| siphon | sacar con un sifón |
| Siphonophora | Siphonophora |
| Sipoo | Sipoo |
| SIPP memory | SIPP |
| Sippar | Sippar |
| Sippe | Sippe |
| sippy cup | vaso infantil |
| Siptah | Siptah |
| Sipuncula | Sipuncula |
| Sipán | Señor de Sipán |
| sir | señor |
