- synThat has a torsion angle between 0° and 90°.
- symplesiteA triclinic-pinacoidal mineral containing arsenic, hydrogen, iron, and oxygen.
- syn-identical
- syncerebrumThe supraesophageal glanglia or brain of many invertebrates.
- synzeugmaA type of zeugma in which a verb joins and governs two phrases by coming between them; a synonym of mesozeugma.