I would be inclined to link it with
Adelaide if it's a variation of a more common name, however I'd look first at a Scandinavian derivation, given the 'dis' ending (c/f
Eydis,
Vigdis,
Tordis et al).
♦ Chrisell ♦
All we have to decide is what to do with the time that is given us. - J.R.R. Tolkien.