electron(n = noun.object) negatron - an elementary particle with negative charge;
is a kind of lepton
has particulars: delta ray, free electron, photoelectron, valence electron

1.  Amber; also, the alloy of gold and silver, called electrum. [1913 Webster]

2.  one of the fundamental subatomic particles, having a negative charge and about one thousandth the mass of a hydrogen atom. The electron carries (or is) a natural unit of negative electricity, equal to 3.4 x 10-10 electrostatic units, and is classed by physicists as a lepton. Its mass is practically constant at the lesser speeds, but increases due to relativistic effects as the velocity approaches that of light. Electrons are all of one kind, so far as is known. Thus far, no structure has been detected within an electron, and it is probably one of the ultimate composite constituents of all matter. An atom or group of atoms from which an electron has been detached has a positive charge and is called a cation. Electrons are projected from the cathode of vacuum tubes (including television picture tubes) as cathode rays and from radioactive substances as the beta rays. Previously also referred to as corpuscle, an obsolete term. The motion of electrons through metallic conductors is observed as an electric current. A particle identical to the electron in mass and most other respects, but having a positive instead of a negative charge, is called a positron, or antielectron [Webster 1913 Suppl.]

electron, n. a stable elementary particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

Idiom:
electron beam a stream of electrons in a gas or vacuum. electron diffraction the diffraction of a beam of electrons by atoms or molecules, used for determining crystal structures etc. electron gun a device for producing a narrow stream of electrons from a heated cathode. electron lens a device for focusing a stream of electrons by means of electric or magnetic fields. electron microscope a microscope with high magnification and resolution, employing electron beams in place of light and using electron lenses. electron pair an electron and a positron. electron spin resonance a spectroscopic method of locating electrons within the molecules of a paramagnetic substance.

Usage:
Abbr.: ESR.

Etymology:
ELECTRIC + -ON

electron accelerator, electron beam, electron emission, electron gun, electron lens, electron microscope, electron microscopic, electron microscopy, electron multiplier, electron optics, electron orbit, electron paramagnetic resonance, electron radiation, electron shell, electron spin resonance, electron tube, electron volt, free electron, valence electron