growth hormone noun7 •A polypeptide hormone, secreted by the pituitary gland in many animals including humans, that promotes growth and regulates the metabolism of carbohydrates, proteins and lipids. •The human homologue specifically: human growth hormone. •A synthetic substance that produces similar effects in the body. •somatropin, an rhGH (for humans). •somatrem, an rhGH (for humans). •rBST (for cattle). •rBGH (for cattle). formsgrowth hormones