- SistineOf or pertaining to Pope Sixtus.
- sextoA book consisting of sheets each of which is folded into six leaves.
- sextainA stanza of six lines; a sestine or sestina.
- sextatemethylcyclohexyl acetate
- sextuplea sixfold amount
- sixteThe sixth defensive position, with the sword hand held at chest height, and the tip of the sword at eye level.