Home › Words › U › unmasterunmasterunmaster means to undo or reverse the mastery or mastership of.Among words judged in Lexicurio's Arena, unmaster ranks #16,733 of 42,747 for Qualifying.EtymologyFrom un- + master.verbTo undo or reverse the mastery or mastership of.Definitions & examples from Wiktionary (CC BY-SA 3.0).