ACE inhibitor UK /ˈeɪs ɪnˌhɪb.ɪ.tə/US /ˈeɪs ɪnˌhɪb.ɪ.tɚ/ noun1 •Any of a class of blood pressure-lowering drugs, including captopril and enalapril, that cause the arteries to widen by preventing the synthesis on angiotensin. formsACE inhibitors