WordReference Random House Unabridged Dictionary of American English © 2026
char•mo•ni•um
(chär mō′nē əm),USA pronunciation n. [Physics.]
- Physicsany meson composed of a charmed quark and a charmed antiquark.
- charm1 + -onium, probably extracted from positronium 1970–75
'charmonium' also found in these entries (note: many are not synonyms or translations):