It would be nice if 'witch' were not so culture-centric. The concept of witch is much broader than that of the celts. Classical literature and mythology is full of people with powers - remember Hecate, after all, is Greek. Thracian witches are a commonplace of Greek and Latin literature - Horace's Satire 1 is a mockery of witch-women doing some kind of ritual in a graveyard and being scared off. --
MichaelTinkler