| Synsystematik | syntaxonomy |
| Systematik | systematics |
| unsystematisch | unsystematic |
| Synsemantikon | function word |
| Synsemantikum | synsemantic word |
| Tonsystem | pitch space |
| Typsystem | type system |
| Subsystem | subsystem |
| systematisch | systematic systematical |
| systemoid | systemoid |
| Nystatin | nystatin |
| Kinematik | kinematics |
| Psychosomatik | psychosomatic medicine |
| synsemantisch | synsemantic |
| Synoptik | synoptic meteorology |
| Syntänie | synteny |
| Synästhesie | synesthesia synaesthesia synæsthesia |
| Sternsystem | star system |
| Soundsystem | sound system |
| Exosystem | exosystem |