/ Dictionary / Index A afterheat: Meaning and Definition of Find definitions for: af•ter•heat Pronunciation: (af'tur-hēt", äf'-), [key] — n. Physics. the heat generated by radioactivity remaining in a nuclear reactor after it has been shut down. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. afterguard after-hours Related Content Daily Word Quiz: wary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language