An Etymological Dictionary of the German Language/Annotated/wachsen
wachsen, verb, ‘to grow, increase, thrive,’ from the equivalent Middle High German wahsen, Old High German wahsan, strong verb; corresponding to the equivalent Gothic wahsjan, Old Saxon wahsan, Dutch wassen, Anglo-Saxon weaxan, English to wax. The Teutonic root wahs contained in these words, and perhaps cognate with that of wecken, appears in non-Teutonic as weks, uks; compare Sanscrit vakš, ukš, ‘to grow strong or tall,’ Zend uχš, Greek ἀέξω (αὐξάνω), ‘to strengthen, increase, grow’; compare Ochse.