Where does “undydd” come from?

undydd (Welsh) comes from Welsh dydd, from Middle Welsh dyð, from Old Welsh did, 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.

undydd (Welsh): a period of one day

Definitions

  1. a period of one day

Ancestry of “undydd”, step by step

undydd traces back through two separate lines of ancestry.

via Welsh dydd

StepLanguageWordMeaning
1Welshdyddday, daytime
2Middle Welshdyðday
3Old Welshdidday
4Proto-Brythonicdiðday, daytime
5Proto-Celticdīyosday
6Proto-Indo-Europeandyḗwssky, heaven; sky god
7Proto-Indo-Europeandyéwssky, heaven
8Proto-Indo-Europeandyew-to be bright; sky, heaven

via Welsh un

StepLanguageWordMeaning
1Welshunonly; one; one, individual
2Middle Welshunone
3Proto-Brythonicʉnone
4Proto-Celticoinosone
5Proto-Indo-Europeanóynosone; single
Every word from Proto-Indo-European dyew- →Every word from Proto-Indo-European dyéws →Every word from Proto-Indo-European dyḗws →