/ Dictionary / Index M MLS: Meaning and Definition of Find definitions for: MLS Pronunciation: [key] Multiple Listing Service. M.L.S. Pronunciation: [key] Master of Library Science. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mls (Thesaurus) MLR MLU Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language