Where does “Kaufer” come from?

Kaufer (English) comes from German Käufer, from German käufen, from Middle High German koufen, from Old High German koufen, from Proto-Germanic *kaupijan.

Ancestry of “Kaufer”, step by step

StepLanguageWordMeaning
1GermanKäuferagent noun of kaufen; shopper, buyer
2GermankäufenAlternative form of kaufen
3Middle High Germankoufen
4Old High Germankoufento buy
5Proto-Germanic*kaupijan
Every word from Proto-Germanic *kaupijanEvery word from Old High German koufenEvery word from Middle High German koufen