Where does “ieith” come from?

ieith (Middle Welsh) comes from Proto-Brythonic jeiθ, from Proto-Celtic yextis, from Proto-Indo-European yek- — to utter.

Ancestry of “ieith”, step by step

StepLanguageWordMeaning
1Proto-Brythonicjeiθlanguage
2Proto-Celticyextislanguage, speech
3Proto-Indo-Europeanyek-to utter

Words derived from “ieith”

Every word from Proto-Indo-European yek- →Every word from Proto-Celtic yextis →Every word from Proto-Brythonic jeiθ →