ETYM Old Eng. erraunt, errant, errand, equiv. to Eng. errant wandering, which was first applied to vagabonds, as an errant rogue, an errant thief, and hence passed gradually into its present and worse sense. Related to Errant.
Without qualification; used informally as (often pejorative) intensifiers; SYN. complete, consummate, double-dyed, everlasting, gross, perfect, pure, sodding, stark, staring, thoroughgoing, utter.
Downright; unmitigated; infamous.