An Etymological Dictionary of the German Language/Schwank

by Friedrich Kluge

Schwank, m.. ‘prank, drollery, farce,’ from late MidHG. swanc (g or k), m., ‘prank, trick, an anecdote about it,’ identical with MidHG. swanc, ‘swing, stroke, cut’ (see Schwang), OHG. swanch, m., allied to swingan (just as OHG. chlanch to chlingan; see Klang).