electron

UK: /ɪˈlɛktrɒn/ US: /ɪˈlɛktrɑn/ ,(i lek′tron)

WordReference Random House Learner's Dictionary of American English © 2025

e•lec•tron /ɪˈlɛktrɑn/   n. [countable]

1. Physics, Electricity a fundamental particle that has a negative charge and exists outside the nucleus of an atom.

WordReference Random House Unabridged Dictionary of American English © 2025

e•lec•tron  (i lek′tron), n. 

1. Chemistry, Physics, Physics Also called negatron. [Physics, Chem.] 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.
2. Electricity a unit of charge equal to the charge on one electron.

• electr(ic) + -on (from the names of charged particles, as ion, cation, anion) with perh. accidental allusion to Greek é̄lektron amber (see electric) term first suggested in 1891 by Irish physicist German. J. Stoney (1826–1911)

Collins Concise English Dictionary © HarperCollins Publishers::

electron / ɪˈlɛktrɒn/ noun

1. a stable elementary particle present in all atoms, orbiting the nucleus in numbers equal to the atomic number of the element in the neutral atom; a lepton with a negative charge of 1.602 176 462 × 10^–19 coulomb, a rest mass of 9.109 381 88 × 10^–31 kilogram, a radius of 2.817 940 285 × 10^–15 metre, and a spin of

Etymology: 19th Century: from electro- + -on