mucin

n. [ From Mucus. ] 1. (Bot. Chem.) See Mucedin. [ Obs. ] [ 1913 Webster ]

2. (Physiol. Chem.) Any of a class of high molecular weight glycoproteins which are contained in mucus, and give to the latter secretion its peculiar ropy character. They are found in all the secretions from mucous glands, and also between the fibers of connective tissue, as in tendons. They form viscous solutions and serve to provide lubrication for movement within body cavities, and some protection of surfaces. See Illust. of Demilune. [ 1913 Webster +PJC ]