meson

  1. Noun.  (rare, _) The mesial plane dividing the body into similar right and left halves.
  2. Noun.  (obsolete) A member of a group of subatomic particles having a mass intermediate between electrons and protons. (The most easily detected mesons fit this definition.).
  3. Noun.  (context, now specifically) An elementary particle that is composed of a quark and an antiquark, such as a kaon or pion. (Meson composed of rarer quarks are much heavier.).

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.