/ Dictionary / Index M MSH: Meaning and Definition of Find definitions for: MSH Pronunciation: [key] Also calleda hormone, produced in vertebrates by the pituitary gland, that causes dispersal of the black pigment melanin of melanocytes. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: msh (Thesaurus) M.Sgt. M.S.H.A. Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language