/ Dictionary / Index T thermal radiation: Meaning and Definition of Find definitions for: ther'mal radia'tion Pronunciation: [key] — Thermodynam. Thermodynam. electromagnetic radiation emitted by all matter above a temperature of absolute zero because of the thermal motion of atomic particles. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thermal printer thermal spring Related Content Daily Word Quiz: ravenous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language