Where does “dydd Llun” come from?

dydd Llun (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.

dydd Llun (Welsh): Monday

Definitions

  1. Monday

Ancestry of “dydd Llun”, step by step

dydd Llun traces back through 3 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 Latin dies Lūnae

StepLanguageWordMeaning
1Latindies LūnaeMonday
2Ancient Greekσελήνηmoon; month; a moon-shaped cake
3Ancient GreekΣέλαςlight, brightness, the bright flame or blaze of fire

via Welsh llun

StepLanguageWordMeaning
1Welshllunshape, figure, form; picture, drawing,...
Every word from Proto-Indo-European dyew- →Every word from Proto-Indo-European dyéws →Every word from Proto-Indo-European dyḗws →