The Proto-Indo-European word *dei-
Word *dei-
Meaning to shine, to be bright
See also Proto-Indo-European: *dye(u)- ‘day’
Proto-Indo-European: *dyḗusphatḗr ‘sky-father’
Synonyms *ĝhel-1, ĝhelǝ-, ĝhlē-, *k̂euk-, *bʰeh₂-, *bʰlēiĝ, *ghel-, *h₂eug-

Comments
Mallory J.P. and Adams D. (2006)