/ Dictionary / Index E emissivity: Meaning and Definition of Find definitions for: em•is•siv•i•ty Pronunciation: (em"u-siv'i-tē, ē'mu-), [key] — n. Thermodynamics. the ability of a surface to emit radiant energy compared to that of a black body at the same temperature and with the same area. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. emissive emit Related Content Daily Word Quiz: cetacean Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language