• synonyms


[em-uh-siv-i-tee, ee-muh-]
noun Thermodynamics.
  1. 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.
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Origin of emissivity

First recorded in 1875–80; emissive + -ity
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for emissivity

Historical Examples

  • The emissivity increases with the temperature, else no state of thermal equilibrium could be reached.

    Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2


British Dictionary definitions for emissivity


  1. a measure of the ability of a surface to radiate energy; the ratio of the radiant flux emitted per unit area to that emitted by a black body at the same temperatureSymbol: ε
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012