Breadcrumb Home > Dictionary > Index S sly: Meaning and Definition of Find definitions for: sly Pronunciation: (slī), [key] — adj., n. sly•er sli•er, sly•est sli•est, —adj. cunning or wily: sly as a fox. stealthy, insidious, or secret. playfully artful, mischievous, or roguish: sly humor. —n. secretly; furtively: a tryst on the sly. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sly (Thesaurus) slutty slyboots TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: recidivism Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language