English Reference
noun

electron

n.
US /ˌɪˈɫɛktɹɑn/ UK /ɪlˈɛktɹɒn/ elec·tron UK spelling electron's, electron's

  1. 01 B2 Upper Intermediate Technical Science

    a very small part of an atom that carries a negative electrical charge.

    a subatomic particle with a negative elementary electric charge that orbits the atomic nucleus.

    Simple

    Electricity is created when electrons move from one atom to another through a wire.

    In context

    In a covalent bond, atoms achieve stability by sharing pairs of electrons, effectively filling their outermost shells.

    Usage

    Countable noun; often used in the plural when discussing electrical flow or chemical bonding.

  2. 02 C2 Proficiency ArchaicTechnical Science

    a type of strong, light metal made from magnesium that was used in the past.

    a trademarked series of magnesium alloys containing varying amounts of aluminium or zinc, historically significant in early twentieth-century engineering.

    Simple

    The old airplane engine was made from a lightweight electron alloy.

    In context

    The structural integrity of the vintage airframe relied on electron components, which offered an exceptional strength-to-weight ratio for the period.

    Teacher's tip

    This sense is largely historical and refers to a specific brand of alloy; modern speakers almost exclusively use the word to refer to the subatomic particle.

Usage electron volts

At the same time, they can still affect moving electrons in ways that could be useful for future electronic devices.

Phys.org· 16 Aug 2026

It is what British science excels at, leading to the discovery of the electron, the structure of DNA and the development of the first computer.

BBC News· 18 Mar 2026

Blend of electric + ion, coined by Anglo-Irish scientist George Stoney in 1891, changed by him multiple times from an earlier electrolion and original electrine (used as early as 1874) as the name for the electric charge associated with a univalent ion. Compare electro-, -on. The particle ("corpuscule") was discovered in 1896. The name electrion was proposed for the particle in 1906 but curtailed because Hendrik Lorentz preferred electron.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated