/ Dictionary / Index L L.C.M.: Meaning and Definition of Find definitions for: L.C.M. Pronunciation: [key] least common multiple; lowest common multiple. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lcm (Thesaurus) L.C.L. LCM chair Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language