/ Dictionary / Index B baryon: Meaning and Definition of Find definitions for: bar•y•on Pronunciation: (bar'ē-on"), [key] — n. Physics. a proton, neutron, or any elementary particle that decays into a set of particles that includes a proton. Cf. quark model. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: baryon (Thesaurus) barye baryon number Related Content Daily Word Quiz: overture Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language