An Etymological Dictionary of the German Language/Annotated/trauen

by Friedrich Kluge

trauen, verb, ‘to trust, confide; marry,’ from Middle High German trûwen, weak verb, ‘to hope, believe, trust’ (also ‘to betroth, unite in marriage’), Old High German trûên (trûwên), ‘to believe, trust.’ Compare Gothic trauan, weak verb, ‘to trust, confide,’ Old Saxon trûôn, Dutch vertrouwen, ‘to trust, confide’ (but trouwen, ‘to marry’). A derivative of the Teutonic root trū̆, treu, ‘to have confidence,’ mentioned under traut and treu.