*idisiz

Unknown. Appears to be from a Proto-Indo-European s-stem, perhaps *h₂idʰ-és- (‘fire, flame, burning’), from *h₂eydʰ- (compare Proto-Germanic *aidaz, *ailą (‘fire’) and *aisǭ (‘fireplace’), and for the s-stem perhaps Albanian jezull (‘cloud of ashes’)); subsequently converted into an archaic i-stem, if this reconstruction is correct. The semantic development, albeit difficult, would have to be “fiery one” → “goddess” or similar.

Alternatively, related to *dīsiz. Kroonen (20, 97) states (on *dīsi-) “Within Germanic, *dīsi- can alternatively be linked to *edis- (q.v.), but this would imply that the word is of non-Indo-European origin.”