uninformEtymologyFrom un- + inform, or a back-formation from uninformed.uninform means to revert (someone) to an uninformed state; reverse the informing of. Lexicurio rates it Rare gem — a strength score of 72 out of 100.verbTo revert (someone) to an uninformed state; reverse the informing of“After the coroner is informed, it's virtually impossible to uninform him!”