Old English growan (of plants) "to grow, flourish, increase, develop, get bigger" (class VII strong verb; past tense greow, past participle growen), from Proto-Germanic *gro- (cf. Old Norse groa, Old Frisian groia, Dutch groeien, Old High German gruoen), from PIE root *ghre- (see grass). Applied in Middle English to human beings (c.1300) and animals (early 15c.) and their parts, supplanting Old English weaxan (see wax (v.)).
