Where does “tanwyr” come from?

tanwyr (Welsh) comes from Welsh tân, from Middle Welsh tan, from Proto-Brythonic tan, from Proto-Celtic teɸnets, from Proto-Indo-European tep- — to be warm, be hot.

Ancestry of “tanwyr”, step by step

tanwyr traces back through two separate lines of ancestry.

via Welsh tân

StepLanguageWordMeaning
1Welshtânfire
2Middle Welshtan—
3Proto-Brythonictanunder; fire
4Proto-Celticteɸnetsfire
5Proto-Indo-Europeantep-to be warm, be hot

via Welsh ŵyr

StepLanguageWordMeaning
1WelshŵyrSoft mutation of gŵyr; grandson, grandchild
2Middle WelshwyrSoft mutation of gwyr
Every word from Proto-Indo-European tep- →Every word from Proto-Celtic teɸnets →Every word from Proto-Brythonic tan →