| Symbolist painters | Symbolisme |
| symbolize | symbolisere |
| symmetrical | symmetrisk |
| Symmetry in mathematics | Symmetri |
| Symmetry in physics | Symmetri |
| Symmetry of second derivatives | Clairauts sætning |
| sympathetic nervous system | sympatiske nervesystem |
| Symphonia | Drejelire |
| Symphonic metal | Symfonisk metal |
| Symphonie | Symfoni |
| Symphonie fantastique | Symphonie Fantastique |
| symphony | symfoni |
| Symphoricarpos | Snebær |
| Symphyotrichum novae-angliae | Nyengelsk Asters |
| Sympodial | Sympodial |
| Symptom | Symptom |
| synagogue | synagoge |
| Synapsida | Pattedyr |
| Synaptic plasticity | Synaptisk plasticitet |
| synchronised swimming | synkronsvømning |
| synchronize | synkronisere |
| synchronous | synkron |
| Synchronous rotation | Bunden rotation |
| syndicate | fagforening |
| syndrome | syndrom |
| synecology | synøkologi |
| Synedrion | Synedrium |
| Synergetics | Synergi |
| Synesthesia | Synæstesi |
| Syngnathidae | Nålefisk-familien |
| Syngnathiformes | Hundestejle |
| Synodic period | Siderisk |
| Synonym | Synonym |
| Synoptic gospels | Synoptiske evangelier |
| Syntactic stylistics | Syntaks |
| syntax | syntaks |
| Syntax of programming languages | Syntaks |
| Synth | Synthesizer |
| Synth pad | Po |
| Synthesizer | Synthesizer |
| Synthetic aperture radar | Synthetic aperture radar |
| Synthetic language | Flekterende sprog |
| Synthetic languages | Flekterende sprog |
| syphilis | syfilis |
| Syracusa | Siracusa |
| Syracuse | Siracusa |
| Syrena | Havfrue |
| Syria | Syrien |
| Syrian | Syrien |
| Syrian Arab Republic | Syrien |
| Syrian Hamster | Guldhamstere |
| Syringa vulgaris | Almindelig Syren |
| Syringe | Indsprøjtning |
| syrup | sirup |
| Sysselmann | Sysselmænd på Færøerne |
| system | system |
| System Center Operations Manager | MOM |
| System engineering | Projektledelse |
| System of a Down | System of a Down |
| System of a Down discography | System of a Downs diskografi |
| System of law | Jura |
| Systema | System |
| Systema Naturae | Videnskabeligt artsnavn |
| Systematic element name | Midlertidige navne til grundstoffer |
| Systematics | Systematik |
