Standard Lemma guide

tachyon

noun · 2 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

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • Received-Pronunciation: /ˈtæk.i.ɒn/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • General-American: /ˈtæ.kiˌɑn/

1

noun

Meaning 1

A hypothetical particle that travels faster than the speed of light.

Definition source: English Wiktionary via Wiktextract

Usage: particle

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

A flaw in a physical theory that predicts the existence of tachyons or similar paradoxical results. Compare with ghost.

Definition source: English Wiktionary via Wiktextract

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

Formed as: tachy- + -on, from ταχύς (takhús, “swift”, “rapid”). Coined by American physicist Gerald Feinberg in 1967.

Across languages

Translations

41 source translations are retained for this English entry.

  • Albanian: takion — hypothetical particle
  • Arabic: تَكْيُون (takyūn) — hypothetical particle
  • Armenian: տախիոն (taxion) — hypothetical particle
  • Bengali: ট্যাকিয়ন (ṭêkiẏon) — hypothetical particle
  • Catalan: taquió — hypothetical particle
  • Chinese Mandarin: 快子 (kuàizǐ) — hypothetical particle
  • Danish: takyon — hypothetical particle
  • Esperanto: taĥiono — hypothetical particle
  • Estonian: tahhüon — hypothetical particle
  • Finnish: takioni — hypothetical particle
  • French: tachyon — hypothetical particle
  • Georgian: ტაქიონი (ṭakioni) — hypothetical particle
  • German: Tachyon — hypothetical particle
  • Greek: τάχυον (táchyon) — hypothetical particle
  • Hebrew: טכיון — hypothetical particle
  • Icelandic: hraðeind — hypothetical particle
  • Indonesian: takhion — hypothetical particle
  • Italian: tachione — hypothetical particle
  • Japanese: タキオン (takion) — hypothetical particle
  • Japanese: 陰子 (inshi) — hypothetical particle
  • Khmer: សីឃាណូ (sey khea no) — hypothetical particle
  • Korean: 타키온 (takion) — hypothetical particle
  • Lithuanian: tachionas — hypothetical particle
  • Malay: takion — hypothetical particle
  • Norwegian Bokmål: takyon — hypothetical particle
  • Norwegian Nynorsk: takyon — hypothetical particle
  • Occitan: taquion — hypothetical particle
  • Persian: تاکیون — hypothetical particle
  • Polish: tachion — hypothetical particle
  • Portuguese: táquion — hypothetical particle
  • Portuguese: taquião — hypothetical particle
  • Romanian: tahion — hypothetical particle
  • Russian: тахио́н (taxión) — hypothetical particle
  • Serbo-Croatian: takion — hypothetical particle
  • Slovak: tachyón — hypothetical particle
  • Slovene: tahion — hypothetical particle
  • Spanish: taquión — hypothetical particle
  • Swedish: takyon — hypothetical particle
  • Thai: แทคีออน — hypothetical particle
  • Turkish: takyon — hypothetical particle
  • Ukrainian: тахіо́н (taxión) — hypothetical particle