n.
Pronunciation: ˌ e-m ə - ' si-v ə -t ē , ˌ ē - ˌ mi- ' siv-
Function: noun
Inflected Form: plural -ties
Date: 1880
: the relative power of a surface to emit heat by radiation : the ratio of the radiant energy emitted by a surface to that emitted by a blackbody at the same temperature