Wiktionary
melanocortin
n. Any of a group of pituitary peptide hormones
Wikipedia
Melanocortin
The melanocortins are a group of peptide hormones which include adrenocorticotropic hormone (ACTH) and the different forms of melanocyte-stimulating hormone (MSH), and are derived from proopiomelanocortin (POMC) in the pituitary gland. The melanocortins exert their effects by binding to and activating the melanocortin receptors.