An Etymological Dictionary of Astronomy and Astrophysics

To increase by natural development, as any living organism or part by assimilation of nutriment; increase in size or substance (Dictionary.com).

Etymology (EN): From M.E. growen, O.E. growan; cf. Du. groeien, O.H.G. grouwan;
PIE base *ghre- “to grow, become green,” from which is also derived grass.

Etymology (PE): Ruyidan, rostan “to grow,” from Mid.Pers. rôditan, rustan “to grow;” Av. raod- “to grow, sprout, shoot,” with fra- “to grow up, shoot forth;” cf. Skt. ruh- “to grow, develop, ascend, climb,” rohati “grows,” rudh- “to grow, sprout, shoot,” rodhati “grows.”