kern

From Middle English curn, cooren, variant forms of Middle English corn, see English corn and also Dutch kern, Old High German kerno, cherno, Middle High German kerne, kern, German Kern (“core, kernel”), Old Norse kjarni, Icelandic kjarni, Danish kjerne, Swedish kärna (“core, kernel”); see also kernel.

From French carne (“corner; projecting angle; quill of a pen”), from Latin cardinem (“hinge”) or from Etymology 1. The verb is a back-formation from kerned, which is from the noun. Doublet of cardo.

From Middle English kerne, from Middle Irish ceithern. Doublet of quaternion.