From Middle English warloghe, warlowe, warloȝe, from Old English wǣrloga (“traitor, deceiver”, literally “truce-breaker”), from wǣr (“covenant, truce, pact, promise”) (from Proto-Indo-European *wēr- (“true”); compare veritable) + loga (“liar”), from Proto-Germanic *lugô, related to Old English lēogan (whence English lie). The hard -ck ending originated in Scottish and Northern English, like the sense "male magic-user" (from the notion that such men were in league with the Devil). Cognate with Old High German wārlogo (“truce-breaker, traitor”).
A few writers have alternatively proposed that the word derives from Old Norse varðlokkur (“caller of spirits”), but as the OED notes, this is implausible due to the extreme rarity of the Norse word and the fact that forms without hard -k, which are consistent with the Old English etymology (“traitor”), are attested earlier than forms with -k (and forms with -ð- are not attested).
warlock (plural warlocks)
- A male magic-user; a male witch.
- (Can we verify(+) this sense?) A traitor or oath-breaker.
- (Can we verify(+) this sense?) The Devil, Satan; a demon.
- Because of its etymology, the term is not much used by male witches themselves, who often identify as witches instead.