An Etymological Dictionary of the German Language/Annotated/Tugend

Tugend, feminine, ‘virtue, chastity,’ from Middle High German tugent, tugende, feminine, ‘manly excellence, power, good quality, virtue’; Old High German tugund, feminine, as a derivative of tugan (see taugen), signifies literally ‘serviceableness, fitness.’ Gothic *dugunþus (derivative unþu-, from pre-Teutonic entu-) is also indicated by Anglo-Saxon duguþ.