/ Dictionary / Index P pertinacity: Meaning and Definition of Find definitions for: per•ti•nac•i•ty Pronunciation: (pûr"tn-as'i-tē), [key] — n. the quality of being pertinacious; persistence. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pertinacity (Thesaurus) pertinacious pertinent Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language