What does arrant mean?
The definition of arrant
Ar”rant, a.
Etym: [OE. erraunt, errant, errand, equiv. to E. 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. See Errant.]

Notoriously or preëminently bad; thorough or downright, in a bad sense; shameless; unmitigated; as, an arrant rogue or coward. I discover an arrant laziness in my soul. Fuller.
2 Thorough or downright, in a good sense. [Obs.] An arrant honest woman. Burton.