| Synergie | synergy |
| Energie | energy |
| Synesis | constructio ad sensum |
| Syntänie | synteny |
| Bioenergie | bioenergy |
| Energie- | energetic |
| Ökoenergie | green energy green power |
| Allergie | allergy |
| Scherge | henchman grunt vassal |
| Syzygie | syzygy |
| Synagoge | synagogue synagog shul temple |
| Synapse | synapse |
| Synchronie | synchrony |
| Syndrom | syndrome |
| Synkope | syncope fainting |
| Synode | synod ecclesiastical council |
| Synonymie | synonymy |
| Synopse | synopsis |
| Synoptik | synoptic meteorology |
| Syntagma | syntagma |