Pronunciation: (mē'zon, -son, mez'on, mes'-), [key]
Physics.any hadron, or strongly interacting particle, other than a baryon. Mesons are bosons, having spins of 0, 1, 2, …, and, unlike baryons, do not obey a conservation law. Cf. quark model.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.