An Etymological Dictionary of the German Language/Annotated/Klepper

by Friedrich Kluge

Klepper, masculine, ‘nag,’ early Modern High German, originally not in a contemptuous sense; a Low German form; it is connected with Low German kleppen, ‘to strike rapidly’ (especially also ‘to ring with a sharp sound’), Middle High German klepfen. Perhaps the term Klepper is derived from the bells on the harness of the horse.