Where does “Marghasyow” come from?

Marghasyow (Cornish) comes from Cornish dy'Yow, from Latin dies iovis, from Latin diēs, from Proto-Italic djēm, from Proto-Italic *djous, from Proto-Indo-European dyḗws, from Proto-Indo-European dyéws, from Proto-Indo-European dyew- — to be bright; sky, heaven.

Ancestry of “Marghasyow”, step by step

Marghasyow traces back through two separate lines of ancestry.

via Cornish dy'Yow

StepLanguageWordMeaning
1Cornishdy'YowThursday
2Latindies iovisThursday
3LatindiēsA day, particularly
4Proto-Italicdjēmaccusative singular of *djous
5Proto-Italic*djous
6Proto-Indo-Europeandyḗwssky, heaven; sky god
7Proto-Indo-Europeandyéwssky, heaven
8Proto-Indo-Europeandyew-to be bright; sky, heaven

via Cornish marghas

StepLanguageWordMeaning
1Cornishmarghasmarket
Every word from Proto-Indo-European dyew-