sec (Adjective) — (of champagne) moderately dry.
sec (Noun) — An independent federal agency that oversees the exchange of securities to protect investors.
sec (Noun) — 1/60 of a minute; the basic unit of time adopted under the Systeme International d'Unites.
sec (Noun) — Ratio of the hypotenuse to the adjacent side of a right-angled triangle.