An Etymological Dictionary of the German Language/Faust
Faust, f., ‘fist,’ from the equiv. MidHG. and MidLG. vûst. OHG. fûst, f.; corresponds to AS. fŷst, E. fist, Du. vuist. This term, common to West Teut., is unknown to OIc.; in Goth. it may have been *fûsti- or *fûhsti-, f. The possible loss of a h before st is supported by the connection with Gr. πύξ, ‘with the fist,’ πύγμαχος, ‘boxer,’ πυγμή, ‘fist, boxing,’ Lat. pugnus, ‘fist,’ pŭgil, ‘boxer,’ perhaps also pugio, ‘dagger’ (lit. ‘fist weapon’), and further pugna, pugnare, &c. The comparison of Faust with OSlov. pęstĭ, f., ‘fist,’ is less trustworthy; this is possible only if the assumed Goth. *fûhsti is further derived from fuñhsti-, pre-Teut. pnkstí-; in that case, however, the Gr. and Lat. terms cited would have no connection with the word.