An Etymological Dictionary of the German Language/schwank

by Friedrich Kluge

schwank, adj., ‘staggering, insteady,’ from MidHG. swanc (k), adj., ‘pliant, thin, slender’; so too the equiv. MidHG. kel, AS. swgneor, OIc. svang-r; allied to the root swing, in schwingen; hence schwant is lit. ‘easily swung, pliant.’ With the Teut. cognates Ital. sguancio, ‘wryness,’ has been connected. .