Definition of "alf"

As the Scandinavians were at that time still worshippers of Thor and Odin, the belief in Alfs and Dwarfs accompanied them to their new abodes, and there, as elsewhere, survived the introduction of Christianity.

1828, Thomas Keightley, The Fairy Mythology, volume I, London: William Harrison Ainsworth, page 248

[T]he charm suggests rather that the Ases had sunk to a level where they could be counted together with witches and lesser wights, than that the alfs were seen as godly beings at the time the charm was composed.

2023, Kveldulf Gundarsson, Elves, Wights & Trolls, The Three Little Sisters, page 83