/ Dictionary / Index D D meson: Meaning and Definition of Find definitions for: D meson Pronunciation: [key] — Physics. Physics. a meson with charm +1 or −1, strangeness 0, and isotopic spin . Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. DMDT D.M.L. Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language