Where does “blwyddyn” come from?

blwyddyn (Middle Welsh) comes from Old Welsh bloidin, from Proto-Celtic blēdanī, from Proto-Indo-European bʰloyd- — pale.

Ancestry of “blwyddyn”, step by step

StepLanguageWordMeaning
1Old Welshbloidin—
2Proto-Celticblēdanīyear
3Proto-Indo-Europeanbʰloyd-pale

Words derived from “blwyddyn”

Every word from Proto-Indo-European bʰloyd- →Every word from Proto-Celtic blēdanī →Every word from Old Welsh bloidin →