| 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 |
| Sirrush | Sirrush |
| Sirtaki | Sirtaki |
| sirup | jarabe |
| Sirusho | Sirusho Harutyunyan |
| Sirventes | Sirventés |
| Siryn | Cirene |
| Sisak | Sisak |
| Sisak-Moslavina County | Condado de Sisak-Moslavina |
| sisal | sisal |
| Sisebur | Sisebuto |
| Sisebut | Sisebuto |
| Siselen | Siselen |
| Sisenand | Sisenando |
| Sisikon | Sisikon |
| Sisnando Davides | Sisnando Davidiz |
| Sisowath of Cambodia | Sisowath |
| Sissili | Provincia de Sissili |
| sissy | cobarde |
| Sissy Spacek | Sissy Spacek |
| Sistan and Baluchestan Province | Sistán y Baluchistán |
| Sistars | SiStars |
| Sistema Central | Sistema Central |
| sister | hermana |
| Sister Act | Sister Act |
| sister city | ciudad hermana |
| sister in law | cunada |
| sister-in-law | cuñada |
| sister-wife | coesposa |
| sistergirl | mijita |
| sisterhood | hermandad |
| sisterly | de hermana |
| sisters | hermanas |
| Sistine Chapel | Capilla Sixtina |
| Sistine Chapel ceiling | Bóveda de la Capilla Sixtina |
| Sistine Chapel Choir | Cappella Musicale Pontificia Sistina |
| Sistine Madonna | Madonna Sixtina |
| Sisto Badalocchio | Sisto Badalocchio |
| sistrum | sistro |
| Sisymbrium | Sisymbrium |
| Sisymbrium sophia | Sisymbrium sophia |
| Sisyphus | Sísifo |
| sit | hacer de niñero |
| sit back | relajarse |
| sit down | sentarse |
| sit in | sentarse en |
| sit still | quedarse quieto |
| sit up | quedarse levantado |
| sit-down | huelga de brazos cruzados |
| sit-down strike | huelga de brazos cruzados |
| sit-in | ocupación |
| sit-up | abdominal |
| Sita | Sītā |
| Sitalces | Sitalces |
| Sitamun | Sitamón |
| Sitatunga | Sitatunga |
| sitcom | comedia de enredo |
| site | terreno |
