Warlock

n. [A-S. wærlōga, a belier or breaker of his agreement, word, or pledge, from lōga, a liar.] A male witch; a wizard; a sprite; an imp. [Written also warluck.] Dryden.

It was Eyvind Kallda's crew Of warlocks blue, With their caps of darkness hooded. Longfellow.