/ Dictionary / Index M mendacity: Meaning and Definition of Find definitions for: men•dac•i•ty Pronunciation: (men-das'i-tē), [key] — pl. -ties the quality of being mendacious; untruthfulness; tendency to lie. an instance of lying; falsehood. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mendacity (Thesaurus) mendacious Mende Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language