Where does “deizioù” come from?

deizioù (Breton) comes from Breton deiz, from Proto-Brythonic dið, from Proto-Celtic dīyos, from Proto-Indo-European dyḗws, from Proto-Indo-European dyéws, from Proto-Indo-European dyew- — to be bright; sky, heaven.

Definitions

Ancestry of “deizioù”, step by step

StepLanguageWordMeaning
1Bretondeizday
2Proto-Brythonicdiðday, daytime
3Proto-Celticdīyosday
4Proto-Indo-Europeandyḗwssky, heaven; sky god
5Proto-Indo-Europeandyéwssky, heaven
6Proto-Indo-Europeandyew-to be bright; sky, heaven
Every word from Proto-Indo-European dyew- →Every word from Proto-Indo-European dyéws →Every word from Proto-Indo-European dyḗws →