/ Dictionary / Index P paroxysmal tachycardia: Meaning and Definition of Find definitions for: paroxys'mal tachycar'dia Pronunciation: [key] — Pathol. Pathol. tachycardia that begins and subsides suddenly. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. paroxysm paroxytone Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language