1. A subatomic particle with a mass between that of an electron and a proton, composed of a quark and an antiquark.
Usage: physics; technical

Examples

• Physicists discovered that mesons are unstable particles that decay rapidly.
• The pion is one of the most common types of meson.
• In particle accelerators, scientists study mesons to understand fundamental forces.
• Mesons were first detected in cosmic rays in the 1930s.
• The properties of mesons help explain the strong nuclear force.