/ Dictionary / Index R radiant heat: Meaning and Definition of Find definitions for: ra'diant heat' Pronunciation: [key] — Thermodynam. Thermodynam. heat energy transmitted by electromagnetic waves in contrast to heat transmitted by conduction or convection. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. radiant flux radiant heating Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language