Idun

Iounn

name means "The Rejuvenating One"
married to Bragi
keeper of the apples which keep the gods eternally young

The giant Thiazzi kidnapped her with the aid of Loki.
often times called the Rejuvenating One.
She is the Goddess of youth, fertility and death. When a God begins to age, all they have to do is eat one of these apples and they are instantly young again

Sources: Various include: http://www.ugcs.caltech.edu/~cherryne/myth.cgi/idun.html

Norse/Teutonic Gods and Goddess
God and Goddess Index