warlockyoudaoicibaDictYouDict[warlock 词源字典]
warlock: [OE] Etymologically, a warlock is a ‘liar on oath’, and hence a ‘traitor’ or ‘deceiver’. Indeed, the word originally meant ‘traitor’ in English. It soon broadened out into a general term of abuse, and it was also used as an epithet for the ‘Devil’, but the modern sense ‘evil sorcerer’ did not emerge until the 14th century. It started life as a compound noun formed from wǣr ‘faith, pledge’ (a relative of English very and German wahr ‘true’) and -loga ‘liar’ (a derivative of lēogan, the ancestor of modern English lie).
=> lie, very[warlock etymology, warlock origin, 英语词源]
warlock (n.)youdaoicibaDictYouDict
Old English wærloga "traitor, liar, enemy, devil," from wær "faith, fidelity; a compact, agreement, covenant," from Proto-Germanic *wera- (cognates: Old High German wara "truth," Old Norse varar "solemn promise, vow"), from PIE *were-o- "true, trustworthy" (see very, also Varangian). Second element is an agent noun related to leogan "to lie" (see lie (v.1); and compare Old English wordloga "deceiver, liar").

Original primary sense seems to have been "oath-breaker;" given special application to the devil (c. 1000), but also used of giants and cannibals. Meaning "one in league with the devil" is recorded from c. 1300. Ending in -ck (1680s) and meaning "male equivalent of a witch" (1560s) are from Scottish. Related: Warlockery.