WordNet (r) 3.0 (2006):

hypothalamic releasing factor
    n 1: any of several hormones produced in the hypothalamus and
         carried by a vein to the anterior pituitary gland where
         they stimulate the release of anterior pituitary hormones;
         each of these hormones causes the anterior pituitary to
         secrete a specific hormone [syn: releasing hormone, RH,
         releasing factor, hypothalamic releasing hormone,
         hypothalamic releasing factor]