What would be the original meaning of *Dye:us? How this noun is formed?
Could it be analysed as *dye:u-, *dyeh1u-, *dyeh1-u?, dye-h1u ?
How if *dye:u- < *dyeh1u- <*dyeh1-yu, through dissimilation?
A form *dyeh1-yu would be analogous to *h2we1-yu, cf. Sanskrit Va:yu, the Wind God.
JS Lopes