Where does “treiswyr” come from?

treiswyr (Welsh) comes from Welsh ŵyr, from Middle Welsh wyr — Soft mutation of gwyr.

Ancestry of “treiswyr”, step by step

treiswyr traces back through two separate lines of ancestry.

via Welsh ŵyr

StepLanguageWordMeaning
1WelshŵyrSoft mutation of gŵyr; grandson, grandchild
2Middle WelshwyrSoft mutation of gwyr

via Welsh treisio

StepLanguageWordMeaning
1Welshtreisioto oppress; to rape; to violate
2Welsh-ioForms verbnouns from verbs and other parts of...
Every word from Middle Welsh wyr →Every word from Welsh ŵyr →