An Etymological Dictionary of the German Language/wachsen
wachsen, vb., ‘to grow, increase, thrive,’ from the equiv. MidHG. wahsen, OHG. wahsan, str. vb.; corresponding to the equiv. Goth. wahsjan, OSax. wahsan, Du. wassen, AS. weaxan, E. to wax. The Teut. root wahs contained in these words, and perhaps cognate with that of wecken, appears in non-Teut. as weks, uks; comp. Sans. vakš, ukš, ‘to grow strong or tall,’ Zend uχš, Gr. ἀέξω (αὐξάνω), ‘to strengthen, increase, grow’; comp. Ochse.