Ma'anar ƙamus na kalmar "exothermic" ita ce: alaƙa da ko nuna wani abin da ke fitar da zafi. A wasu kalmomi, halayen exothermic shine wanda ake fitar da makamashi daga tsarin, yawanci ta hanyar zafi, haske, ko sauti. Wannan ya bambanta da halayen endothermic, wanda ke ɗaukar makamashi daga tsarin. Misalan halayen exothermic sun haɗa da konewa, oxidation, da nau'ikan polymerization da yawa. Kishiyar exothermic shine endothermic, wanda ke nufin wani abu wanda ke ɗaukar zafi daga muhalli.