oxytocin: Meaning and Definition of

ox•y•to•cin

1. a polypeptide hormone, produced by the posterior lobe of the pituitary gland, that stimulates contraction of the smooth muscle of the uterus.
2. a commercial form of this substance, obtained from beef and hog pituitary glands or esp. by synthesis, and used chiefly in obstetrics to induce labor and to control postnatal hemorrhage.