Wandering; itinerant; vagrant; errant: as, a knight arrant; an arrant preacher: especially in thief arrant or arrant thief, a roving, outlawed robber; a highwayman. Now written errant.Notorious; manifest; unmitigated; downright: in a bad sense (derived from the noun qualified): as, an arrant rogue; an arrant coward; arrant nonsense.Thorough; downright; genuine: in a good sense.Synonyms Utter, rank, consummate, perfect.