Where does “wethir” come from?

wethir (Middle English) comes from Old English weþer, from Proto-West Germanic weþru, from Proto-Germanic weþruz, from Proto-Indo-European wēt- — year.

Ancestry of “wethir”, step by step

StepLanguageWordMeaning
1Old Englishweþerwether
2Proto-West Germanicweþruyearling lamb; wether, ram
3Proto-Germanicweþruzyearling lamb; wether, ram
4Proto-Indo-Europeanwēt-year
Every word from Proto-Indo-European wēt- →Every word from Proto-Germanic weþruz →Every word from Proto-West Germanic weþru →