An Etymological Dictionary of the German Language/Annotated/Tausch
Tausch, masculine, ‘exchange, barter’; Modern High German only; in late Middle High German (15th century) we meet for the first time with rostiuchœre, ‘horse-dealer’ (compare Dutch paardentuischer), and verûschen, ‘to exchange.’ The word is properly Low German; compare Dutch tuischen, ‘to barter.’ How täuschen, ‘to deceive,’ from late Middle High German tiuschen (tûschen), ‘to deceive, make game of some one’ (late Middle High German tûsch, ‘mockery, joke, deception’), is connected with this word is not clear.