An Etymological Dictionary of the German Language/fach

by Friedrich Kluge

fach, adj., suffix, ‘-fold,’ from MidHG. (very rare) vach, in manecvach, zwivach, OHG. not found; mannigfach, lit. ‘with many divisions’; moreover, MidHG. vach, denotes also ‘fold,’ and -fach as a suffix may be an imitation of the earlier suffix -falt in manecvalt, ‘manifold.’