köken: First attested in 1621. From Celtic, from Proto-Indo-European *gʷew- (“excrement; dung”) + the suffix *-st-; Compare German Kot (“feces”), Welsh budr (“filthy”). Back-formation from bostal (“corral: cattle pen”), from Late Latin bōstar, būstar, from bōs (“bull”) and stāre (“to stand, remain; a standing, habitation”).
köken: Euphemistic form of Jesús minn eini (“Jesus, my one and only”), which may itself be a folk-etymological alteration of Latin Jesu domine (“Lord Jesus”). Compare for this German jemine.