/ Dictionary / Index M mascon: Meaning and Definition of Find definitions for: mas•con Pronunciation: (mas'kon"), [key] — n. Geol. a massive concentration of high-density material beneath the surface of the moon. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mascle mascot Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language