chem·i·sorp·tion noun alsochem·o·sorp·tion\ˌ ̷ ̷ ̷ ̷ˈsȯrpshən\ (-s) Etymology:chem- + sorption : adsorption, especially when irreversible, by means of chemical forces in contrast with physical forces < chemisorption of gaseous nitrogen on iron catalysts >