Where does “fainen” come from?

fainen (Middle English) comes from Old English fæġnian, from Proto-West Germanic faginōn, from Proto-Germanic faginōną, from Proto-Indo-European pōḱ-.

Ancestry of “fainen”, step by step

StepLanguageWordMeaning
1Old Englishfæġnianto rejoice, make glad
2Proto-West Germanicfaginōnto gladden, rejoice
3Proto-Germanicfaginōnąto gladden, rejoice
4Proto-Indo-Europeanpōḱ-—
Every word from Proto-Indo-European pōḱ- →Every word from Proto-Germanic faginōną →Every word from Proto-West Germanic faginōn →