define impeach.
impeach verb [T]. âº to make a âformal âstatement saying that a âpublic âofficial is âguilty of a âserious âoffence in âconnection with âtheir âjob, âespecially in the US: The âgovernor was impeached for âwrongful use of âstate âmoney. impeachable adjective uk us /-ËpiË.tÊÉ.blÌ©/ âº an impeachable âoffence. adjective uk us /-ËpiË.tÊÉ.blÌ©/.