Where does “keen” come from?

Keen comes from Irish caoin, from Old Irish caín, ultimately from Proto-Indo-European ǵneh₃-.

keen (English): Often with a prepositional phrase, or with to and...

Definitions

  1. Often with a prepositional phrase, or with to and...

Ancestry of “keen”, step by step

keen traces back through two separate lines of ancestry.

via Irish caoin

StepLanguageWordMeaning
1Irishcaoinsmooth, delicate, polished; kind, gentle,...
2Middle Irishcaínsmooth finished side; "especially" the outer...
3Old Irishcaínfine, good; fair, beautiful
4Proto-Celtic*kanisnice, good

via Middle English kene

StepLanguageWordMeaning
1Middle Englishkenekeen
2Old Englishcēnekeen, fierce, bold, brave, warlike, powerful;...
3Proto-Germanickōnizable, knowledgeable, skillful, clever
4Proto-Indo-Europeanǵneh₃-to know

Words derived from “keen

Every word from Proto-Celtic *kanisEvery word from Old Irish caínEvery word from Middle Irish caín
keen — Etymology, Origin & Word History | Etymology Explorer