[ myoo-on ]
/ ˈmyu ɒn /

noun Physics.

a lepton similar in most respects to the electron except that it is unstable, it may be positively charged, and its mass is approximately 207 times greater; the positively charged muon is the antiparticle of the negatively charged muon. Symbol: μ

Origin of muon

1950–55; by shortening of mu meson; see mu, -on1


mu·on·ic, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for muon

  • Although the muon does not experience nuclear forces, it can interact weakly with nuclei.

    LRL Accelerators|Lawrence Radiation Laboratory
  • The behavior of the muon is well understood, but its role as one of the elementary particles is unknown.

    LRL Accelerators|Lawrence Radiation Laboratory
  • The muon is unstable, eventually undergoing a radioactive decay into an electron.

    LRL Accelerators|Lawrence Radiation Laboratory
  • That is, if the muon did not exist, what effect would this have on the structure of matter?

    LRL Accelerators|Lawrence Radiation Laboratory

British Dictionary definitions for muon

/ (ˈmjuːɒn) /


a positive or negative elementary particle with a mass 207 times that of an electron and spin 1/2 . It was originally called the mu meson but is now classified as a lepton

Derived forms of muon

muonic (mjuːˈɒnɪk), adjective

Word Origin for muon

C20: short for mu meson
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for muon

[ myōōŏn′ ]

An elementary particle in the lepton family having a mass 209 times that of the electron, a negative electric charge, and a mean lifetime of 2.2 X 10-6 seconds. The muon was originally called the mu-meson and was once thought to be a meson. See Table at subatomic particle.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.