<p><strong>Noun</strong></p><ul><li>Also called negatron.</li><li>Physics, Chemistry. an elementary particle that is a fundamental constituent of matter, having a negative charge of 1.602 × 10−19 coulombs, a mass of 9.108 × 10−31 kilograms, and spin of ½, and existing independently or as the component outside the nucleus of an atom.</li><li>Electricity. a unit of charge equal to the charge on one electron.</li></ul>