They really skipped over the actual original use of the word, which was not witchcraft, but "wyrd", the Anglo-Saxon word for "fate", although according to comme

They really skipped over the actual original use of the word, which was not witchcraft, but "wyrd", the Anglo-Saxon word for "fate", although according to commentaries on Beowulf it was less "inevitable because of (divine) decree", but more towards "inevitable due to the consequences of our actions". "Wyrd" was the the Anglo-Saxon spelling for the Norse "Urd", the well that Odin dropped his eye into in exchange for a draught of its waters of wisdom. The "wyrd sisters" would be Norns, the three women who were the Norse "fates". In a Christian context, of course, trying to access the future as a tool to benefit oneself is forbidden, so someone with access to the wyrd would be a witch. But I would assume different from satanic witches, because source of the knowledge is not demons but a pre-Christian access to the waters of the Well of Urd, the Well of Wyrd. In any case, Shakespeare's wyrd sisters are probably representing the Anglo-Saxon Fates (or "fate" collectively), rather than any modern conception of witches.