An Etymological Dictionary of the German Language/Waise
Waise, f. (m.), ‘orphan,’ from MidHG. weise, OHG. weiso (*weisso?), m., ‘parentless child,’ also ‘fatherless or motherless child’ (the masc. seems to be used in MidHG. for the fem. also); corresponding to Du. wees, OFris. wêsa, ‘orphan.’ The base (Teut. waisjôn?) is probably derived from an Aryan root meaning ‘to rob’; comp. Sans. vidh, ‘to become empty’ (see Witwe). In Goth. a diminutive of Witwe (see Dirne and Eichhorn), widuwaírna, m., signifies ‘orphan.’