Noun

• S: (n) second, sec, s (1/60 of a minute; the basic unit of time adopted under the Systeme International d'Unites)
• S: (n) secant, sec (ratio of the hypotenuse to the adjacent side of a right-angled triangle)
• S: (n) Securities and Exchange Commission, SEC (an independent federal agency that oversees the exchange of securities to protect investors)

Adjective

• S: (adj) sec, unsweet ((of champagne) moderately dry)