/ Dictionary / Index G guileful: Meaning and Definition of Find definitions for: guile•ful Pronunciation: (gīl'ful), [key] — adj. insidiously cunning; artfully deceptive; wily. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: guileful (Thesaurus) guile guileless Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language