@phil777 @MrKawaii The original use of warlock is basically a magic user who can't be trusted by other magic users, generally witches in this case, they might even be a traitorous former member of the coven that considers them a warlock now or something like that.
Witch is originally gender neutral to begin with, but nowadays there's about as many different uses for any of these kinds of terms across various fictional settings as there are different fictional settings. Including males being wizards or warlocks and women being witches, as you said. But since they're calling Zain a witch, they're going with the gender neutral version I'd imagine.