The Scottish literature use "warlock" very much as "sorceror" or "male witch"
William Reid (1764-1831), in "Kate o' Gowrie" speaks of "The darkest night I near nae deil, Warlock, or witch in Gowrie"
In Scott's novel, Redgauntlet ( 1824), we have "Now this was a tune my gudesire learned frae a warlock, that heard it when they were worshipping Satan at their meetings, and my gudesire had sometimes played it at the ranting suppers in Redgauntlet Castle, but never very willingly; and now he grew cauld at the very name of it, and said, for excuse, he hadna his pipes wi' him. "I will delate you for a warlock to the privy council!" said Sir John. "I will send you to your master, the devil, with the help of a tar-barrel and a torch!"
Robert Burns (1759 - 1796) has "Ye surely hae some warlock -breef
Owre human hearts, For ne'er a bosom yet was prief, Against your arts."
Yet there are also peculiar uses of "warlock", as for instance "But the docksy auld laird of the Warlock glen" or the "warlock craigie" when it seems more connected with place than person.
The Anglo-Saxon source is given as "waerloga", "Waerloga", waer = pledge, and loga = liar, but this is unattested in any sources.
Moreover, if it is Anglo-Saxon, why do we find it nowhere in England but everywhere in Scotland, where the Anglo-Saxons and their language did not penerate? That is a major problem, and one I decided to track down.
The Oxford English Doctionary (complete) says that "The modern forms with final -(c)k are of obscure origin, for they appear first in Sc. of the 16th c., and owe their spread to Sc. writers, and so cannot represent, as has been assumed, a Southern sound-substitution of (k) for the -ch (x) of some of the rarer North and Sc. forms. From the first they they have been used in the sense "wizard". Some other word, lost or not discovered , has perh. influenced both form and sense." (OED 1991)
So far, so good.
An alternative etymology has been given as Old Norse, Vard-lokkur, "caller of spirits". I decided to track this down to see if I could find any original sources mention that i could check. I did.
There is a considerably well-researched linguistic article at http://www.boudicca.de/warlock-e.htm, which comments:
"In the Old Norse tale, Eiriks saga Rauða (The Saga of Eirik the Red, mid 14th century), the term "varðlokkur" appears in the context of a prophecy-session at a farm in Greenland. It is used to mean a song of conjuring. When the two constituent terms are split, we see "varð" which had by that time the sense of a spirit, and "lokkur" or a song of luring or attracting. In Modern Swedish, the term "lock" is used for the pastoral songs that are sung to call the cows home from the meadow -- "kolock". In just this same way, the song to attract or call the "varð" or spirit, was the "varðlokkur". Gradually, with time, the term for the song and for the singer became interchangable, i.e., the same term was used for both."
Now recent DNA studies have shown that the north-west of England and Scotland by Norsemen from Norway and Sweden (the Danes going further south, and their DNA undifferenntiable with the Anglo-Saxon). So there are three reasons for seeing this as the source:
1) the migratory path of the scandivanian peoples, carrying their langage with them to scotland, where the anglo-saxon invaders were southern england.
2) the fact that the word can be established in texts
3) the fact that the word occurs in Scotland, but not until much later, in England - hardly what we would expect from an Anglo-Saxon source.
None of this means that "warlocks" existed, but it fits the context much better.
Moreover, some, but not all, of the uses of warlock in the Scottish texts ("a warlock glen") would make better sense as simply "a place of enchantment", as in the context, it has no sinister connotations, but almost the reverse.
Lastly, the composer Phillip Heseltine (1894-1930) took the pseudonymn "Peter Warlock". The choice of that particular nom-de-plume has led to some speculation but, so far, nobody has adequately explained why it should be a source of speculation or, indeed, where it could have come from. It is known that he studied Scottish poems and ballads, and his earliest orchestral work " An Old Song" is based on a Scottish folk song ('There was anes a May'), and walks on the Cornish moors. Could he have been drawing upon this older meaning of warlock, as song of enchantment? This was what he said on the piece:
"The tune should emerge, as from afar, chiming in with one's thoughts while walking. The curious way in which it seems to end on the supertonic gives the impression that it fades away into the distance, unfinished. One stands still, attentive to catch another strain, but there is only the gentle murmur of wind--and only fragments remain in the memory--and a mood half-contented and half-sad. "
Before it was overlaid by demonic connotations in post-Reformation Scotland, and enchantment became associated with evil (hence "warlock" as evil enchanter), might I suggest that the origins lie in a the Norse idea of song of enchantment, and that here we, too, can hear the call of the wild, and the sweet mystery of the "warlock glen" and the "warlock craigie".