An Etymological Dictionary of the German Language/Kleck

by Friedrich Kluge

Kleck, Klecks, m., ‘blot,’ ModHG. simply; only the vb. klecken (klecksen) may be traced farther back, MidHG. klęcken, ‘to blot, stain, sputter,’ also ‘to strike sonorously’; the corresponding klac (ckes), m., signifies ‘rent, slit, crack.’