Standard Lemma guide

fermion

noun · 3 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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  • /ˈfɜːmɪɒn/
  • Southern-England: Recorded audio is listed in the source snapshot.

1

noun

Meaning 1

Any elementary or composite particle that has half-integer spin and thus obeys Fermi–Dirac statistics and the Pauli exclusion principle (equivalently, a particle for which the wavefunction of any system of identical such particles changes sign whenever two are swapped); a baryon, a lepton or a quark;

Definition source: English Wiktionary via Wiktextract

Usage: particle

Qualifier: Standard Model

Topics: natural-sciences, physical-sciences, physics

Examples

  • The fermions treated by the Standard Model are the (composite) baryons and the (elementary) leptons and quarks.
  • According to the spin–statistics theorem, the wavefunction of a system of identical fermions (particles of half-integer spin) is antisymmetric under the operation of swapping any two particles.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

Any elementary or composite particle that has half-integer spin and thus obeys Fermi–Dirac statistics and the Pauli exclusion principle (equivalently, a particle for which the wavefunction of any system of identical such particles changes sign whenever two are swapped); a baryon, a lepton or a quark; (slightly more loosely) any such particle or any composite particle composed of fermions.

any such particle or any composite particle composed of fermions.

Definition source: English Wiktionary via Wiktextract

Usage: particle

Qualifier: Standard Model; slightly more loosely

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

any particle that obeys Fermi-Dirac statistics and is subject to the Pauli exclusion principle

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: particle, subatomic particle

Narrower terms: baryon, heavy particle, lepton

History

Etymology

From Fermi + -on. Named after Italian-American physicist Enrico Fermi. Coined by English physicist Paul Dirac in 1945 in a lecture titled "Developments in Atomic Theory".

Across languages

Translations

33 source translations are retained for this English entry.

  • Arabic: فرميون — particle with totally antisymmetric composite quantum states
  • Armenian: ֆերմիոն (fermion) — particle with totally antisymmetric composite quantum states
  • Basque: fermioi — particle with totally antisymmetric composite quantum states
  • Bengali: ফার্মিয়ন (pharmiẏon) — particle with totally antisymmetric composite quantum states
  • Catalan: fermió — particle with totally antisymmetric composite quantum states
  • Chinese Mandarin: 费米子 (fèimǐzǐ) — particle with totally antisymmetric composite quantum states
  • Czech: fermion — particle with totally antisymmetric composite quantum states
  • Danish: fermion — particle with totally antisymmetric composite quantum states
  • Dutch: fermion — particle with totally antisymmetric composite quantum states
  • Esperanto: fermiono — particle with totally antisymmetric composite quantum states
  • Finnish: fermioni — particle with totally antisymmetric composite quantum states
  • French: fermion — particle with totally antisymmetric composite quantum states
  • German: Fermion — particle with totally antisymmetric composite quantum states
  • Hungarian: fermion — particle with totally antisymmetric composite quantum states
  • Ido: fermiono — particle with totally antisymmetric composite quantum states
  • Italian: fermione — particle with totally antisymmetric composite quantum states
  • Japanese: フェルミ粒子 (ferumi ryūshi) — particle with totally antisymmetric composite quantum states
  • Japanese: フェルミオン (ferumion) — particle with totally antisymmetric composite quantum states
  • Khmer: ផ្វឺរមីយាណូ (fɨɨmiiyion) — particle with totally antisymmetric composite quantum states
  • Mongolian: фермион (fermion) — particle with totally antisymmetric composite quantum states
  • Norwegian Bokmål: fermion — particle with totally antisymmetric composite quantum states
  • Norwegian Nynorsk: fermion — particle with totally antisymmetric composite quantum states
  • Persian: فرمیون (fermiyon) — particle with totally antisymmetric composite quantum states
  • Polish: fermion — particle with totally antisymmetric composite quantum states
  • Brazilian Portuguese: férmion — particle with totally antisymmetric composite quantum states
  • European Portuguese: fermião — particle with totally antisymmetric composite quantum states
  • Russian: фермио́н (fermión) — particle with totally antisymmetric composite quantum states
  • Serbo-Croatian: фермион — particle with totally antisymmetric composite quantum states
  • Serbo-Croatian: fermion — particle with totally antisymmetric composite quantum states
  • Slovene: fermion — particle with totally antisymmetric composite quantum states
  • Spanish: fermión — particle with totally antisymmetric composite quantum states
  • Swedish: fermion — particle with totally antisymmetric composite quantum states
  • Turkish: fermiyon — particle with totally antisymmetric composite quantum states
Real reading context

fermion in complete knowledge articles