A galdr or ġealdor refers to a spell or incantation in Old Norse and Old English respectively; these were usually performed in combination with certain rites.

An incantation, a spell, a charm, an enchantment, or a bewitchery, is a magical formula intended to trigger a magical effect on a person or objects. The formula can be spoken, sung, or chanted. An incantation can also be performed during ceremonial rituals or prayers. In the world of magic, wizards, witches, and fairies are common performers of incantations in culture and folklore.