Old English also had hægtesse "witch, fury", whence Modern English hag, of uncertain origin, but cognate to German Hexe, from an Old High German haga-zussa, Common Germanic *haga-tusjon- (OED), perhaps from a *tesvian "to mar, damage", meaning "field-damager" (the suggestion of Grimm).
The Old English plural form for both the masculine and feminine nouns was wiccan ("witches") and wiccecræft was "witchcraft".