Warlock

Warlocks, this is used in Merlin to indicate a male witch or sorcerer, the series does not discern differences except in gender in terms. That is there is no difference between a witch, sorceress and enchantress as well as there being no difference between warlock, wizards and sorcerers. However many may find the term contraversal as the etymology is generally felt to come from the scottish for oath breaker. However the term is rarely applied using this and the etymology is debatable. Some say its nordic for spell singer or spirit caller along with various other possibilities.

However in terms of the series a warlock is male practitioner of magic and there are no negative or positive allusions to this. The series generally does not make that kind of judgement via terminology like that but rather the virtues and vices of the characters are seen in their actions.

Both Edwin and Merlin are Warlocks, while Edwin was vengeful and worked dark magic Merlin works to save lives.