| 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 |
| Sir Ector | Sir Héctor |
| Sir Francis Haddock | Francisco de Hadoque |
| Sir Gawain and the Green Knight | Sir Gawain y el Caballero Verde |
| Sir Kay | Sir Kay |
| Sir Lionel | Sir Lionel |
| Sir Mix-a-Lot | Sir Mix-a-Lot |
| Sir Seewoosagur Ramgoolam Botanical Garden | Jardín Botánico de Pamplemousses |
| Sir Tor | Torio |
| Sir William Henry Perkin | William Perkin |
| Siracusa | Siracusa |
| Sirah Rasul Allah | Vino Syrah |
| Sirajganj | Sirajganj |
| Sirdarya Province | Región de Sirdarín |
| Sirdaryo | Sir Daria |
| Sirdaryo Province | Sirdarín |
| sire | dueño |
| siren | sirena |
| siren song | canto de sirena |
| Sirenia | Sirenia |
| Sirenik language | Idioma sirenik |
| Sirhan Sirhan | Sirhan Bishara Sirhan |
| Sirikit | Sirikit Rajini |
| Sirikit Rajini | Sirikit Rajini |
| Sirimavo Bandaranaike | Sirimavo Bandaranaike |
| Sirindhorn International Institute of Technology | Instituto Internacional de Tecnología Sirindhorn |
| Sirius | Sirio |
| Sirius Black | Sirius Black |
| Sirkap | Taxila |
| sirloin | lomo |
| sirloin steak | lomo |
| Sirmium | Sirmio |
| sirocco | siroco |
