Idun, or Iduna, in Scandinavian mythology, the goddess of youth and spring. She was daughter of the dwarf Svald and wife of Bragi. She was keeper of the golden apples, the eating of which preserved to the gods their eternal youth. Loki, the evil spirit, kidnapped her and the apples, but was forced by the gods to restore her liberty. Idun personifies the year between March and September, and her myth represents the annual imprisonment of spring by winter.