The word "over-grew" means something that has grown excessively, but its antonyms are words that signify not growing or diminishing. Under-grew, stunted, declined, decreased, shrunk, shrank, and reduced are some of the antonyms for over-grew. When an object is under-grown, it is not yet fully developed, and it often implies a lack of maturity or experience. On the other hand, when an object is stunted, it has achieved its full growth potential and may have a negative connotation. Decreased, shrunk, and shrank suggest contraction or reduction of size or quantity, whereas reduced means that something is made smaller or diminished in intensity. In all, the antonyms for over-grew emphasize a decrease in growth, size or intensity.