An Etymological Dictionary of the German Language/Sohn
Sohn, m., ‘son,’ from the equiv. MidHG. and OHG. sun, earlier OHG. sunu, m.; a common Teut., and further a common Aryan word (comp. Tochter, Vater, and Mutter); corresponding to Goth. sunus, AS. sunu, E. son, Du. zoon, OSax. sunu. To these Sans. sûnú; Zend hunu, OSlov. synŭ, and Lith. sûnús, ‘son,’ are primit. allied. The root sū̆ (comp. Sans. sû, ‘to give birth to’; see Sau), contained in this stem sū̆-nú-, also forms the base of Gr. υἱός (dial. υἱύς), ‘son,’ which points to Aryan sū̆-yú- (suiw-). Comp. Schnur.