An Etymological Dictionary of the German Language/Annotated/Kleck

by Friedrich Kluge

Kleck, Klecks, masculine, ‘blot,’ Modern High German simply; only the verb klecken (klecksen) may be traced farther back, Middle High German klęcken, ‘to blot, stain, sputter,’ also ‘to strike sonorously’; the corresponding klac (ckes), masculine, signifies ‘rent, slit, crack.’