Particle Physics a subatomic particle that cannot be divided, as a lepton, quark, weakon, or classon: in the past any subatomic particle was thought to be an elementary particle
Any subatomic particle, such as one of the fundamental fermions or gauge bosons, that may be a component of other particles but is not made of components itself. Also called fundamental particle.
(plural elementary particles)
- (physics) Fundamental particle; any of the subatomic particles that does not consist of other, smaller particles; the gauge bosons, leptons and quarks.