Where does “gaeafa” come from?

gaeafa (Welsh) comes from Welsh gaeaf, from Middle Welsh gayaf, from Old Welsh gaem, from Proto-Celtic gyemos, from Proto-Indo-European ǵʰyem- — winter.

Ancestry of “gaeafa”, step by step

StepLanguageWordMeaning
1Welshgaeafwinter; Soft mutation of caeaf
2Middle Welshgayaf—
3Old Welshgaem—
4Proto-Celticgyemoswinter
5Proto-Indo-Europeanǵʰyem-winter
Every word from Proto-Indo-European ǵʰyem- →Every word from Proto-Celtic gyemos →Every word from Old Welsh gaem →