/ Dictionary / Index C critical constant: Meaning and Definition of Find definitions for: crit'ical con'stant Pronunciation: [key] — Physics. Physics. any of three constants associated with the critical point of a pure element or compound. Cf. critical density, critical pressure, critical temperature. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. critical angle critical density Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language