Breadcrumb Home > Dictionary > Index C charmonium: Meaning and Definition of Find definitions for: char•mo•ni•um Pronunciation: (chär-mō'nē-um), [key] — n. Physics. any meson composed of a charmed quark and a charmed antiquark. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. charming charm school ✖ Related Content Daily Word Quiz: taradiddle Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language