An Etymological Dictionary of the German Language/Annotated/straff
straff, adjective, ‘stretched, tense, tight,’ from Middle High German (rare) straf(ff), ‘tense, strict’; probably a Low German word corresponding to Dutch straf. Its early history is, however, obscure. It has been supposed that Italian strappare, ‘to tear out,’ is borrowed from Teutonic by assuming a root strap, ‘to draw’; hence straff, literally ‘drawn tight’?.