| syndrom | syndrome |
| Syndrom chińskiej restauracji | Chinese restaurant syndrome |
| syndrom chorego budynku | sick building syndrome |
| syndrom grupowego myślenia | groupthink |
| syndrom jerozolimski | Jerusalem syndrome |
| Syndrom KZ | Survivor syndrome |
| syndrom miodowego miesiąca | honeymoon syndrome |
| syndrom paryski | Paris syndrome |
| Syndrom Piotrusia Pana | Peter Pan syndrome |
| Syndrom Stendhala | Stendhal syndrome |
| syndrom sztokholmski | Stockholm syndrome |
| syndykacja | sindication |
| syndykalista | syndicalist |
| syndykalizm | syndicalism |
| Syndykat | Syndicate |
| synek | sonny |
| synekdocha | synecdoche |
| synekologia | synecology |
| synekura | sinecure |
| Synemur | Sinemurian |
| Synergetyka | Synergetics |
| synergia | synergy |
| synergizm działania pestycydów | interaction of pesticides |
| Synestezja | Synesthesia |
| Synezjusz | Synesius |
| Syngalez | Sinhalese |
| Syngalezi | Sinhalese people |
| Syngalezka | Sinhalese |
| Synkopa | Fainting fit |
| synkretyzm | syncretism |
| Synne bitwy | List of battles |
| Synod | Church congress |
| Synod Jerozolimski | Synod of Jerusalem |
| Synod trupi | Cadaver Synod |
| Synod w Jamni | Council of Jamnia |
| synogarlica senegalska | laughing dove |
| synonim | synonym |
| synonimiczny | synonymous |
| SYNOP | SYNOP |
| synowa | daughter-in-law |
| synowektomia | synovectomy |
| Synowie Bóra | Easterlings |
| Synowie przymierza | Members of the covenant |
| Synowie Wolności | Sons of Liberty |
| syntaksa | syntax |
| Syntaktyka | Syntax |
| Syntaza ATP | ATP synthase |
| syntetyczny | synthetic |
| Syntetyczny izotop promieniotwórczy | Synthetic radioisotope |
| Synteza addytywna | Additive color |
| Synteza Fischera-Tropscha | Fischer-Tropsch process |
| Synteza granularna | Granular synthesis |
| Synteza substraktywna | Subtractive color |
| Synteza subtraktywna | Subtractive color |
| synteza termojądrowa | nuclear fusion |
| Synteza totalna | Total synthesis |
| Syntezator | Synthesizer |
| Syntezator Mooga | Moog synthesizer |
| Synth pop | Synthpop |
| Synthetoceras | Synthetoceras |
| Synton | Synthon |
| syntonizacja | syntonization |
