An Etymological Dictionary of the German Language/Annotated/Kaldaunen
Kaldaunen, feminine plural, ‘intestines,’ from Middle High German and Middle Low German kaldûne; a Middle High German and Low German word (in Upper German Kutteln). It is based upon a Romance and Middle Latin caldûmen, a derivative of Latin calidus (caldus) ‘warm,’ meaning chiefly ‘the still reeking entrails of newly slaughtered animals’; compare. South-West French chaudin, Bologn. caldôm, ‘entrails.’ From East Romance (and German?) the word found its way also into Slavonic; compare Czech kaldoun, ‘entrails,’ Croat. kalduni, ‘lung.’