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.)).
Have you ever heard anything about God, Topsy? ... Do you know who made you?" "Nobody, as I knows on," said the child. ... "I spect I grow'd. Don't think nobody never made me." [Harriet B. Stowe, "Uncle Tom's Cabin," 1851]
v. grew (grōō), grown (grōn), grow·ing, grows
To increase in size by a natural process.
To develop and reach maturity.
To be capable of growth; thrive.