/ Dictionary / Index P pyrazolone: Meaning and Definition of Find definitions for: py•raz•o•lone Pronunciation: (pi-raz'u-lōn", pī-), [key] — n. Chem. any of the group of heterocyclic compounds containing the pyrazoline ring in which one carbon atom is doubly linked to an oxygen atom not in the ring. the parent compound, CHNO. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyrazoline pyrazolone dye Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language