Standard Lemma guide

tritium

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

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: /ˈtɹɪt.i.əm/
  • General-American: /ˈtɹɪt.i.əm/
  • General-American: /ˈtrɪʃ.i.əm/
  • General-American: /ˈtrɪʃ.əm/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • rhymes with -ɪtiəm
  • rhymes with -ɪʃiəm
  • rhymes with -ɪʃəm
  • CMU ARPABET: T R IH1 T IY0 AH0 M Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

A radioactive isotope of the element hydrogen (symbol T, 3H or 31H) having one proton and two neutrons.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: mul:H-3, mul:3H, hydrogen-3, hydrogen 3

Antonyms: none provided

Broader terms: hydrogen, mul:H

2

noun

Meaning 2

An atom of this isotope.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: hydrogen, H, atomic number 1

History

Etymology

Borrowed from New Latin tritium, from Ancient Greek τρίτος (trítos, “third”) + New Latin -ium. By surface analysis, trit- + -ium.

Across languages

Translations

26 source translations are retained for this English entry.

  • Afrikaans: tritium — radioactive isotope of hydrogen
  • Bulgarian: три́тий (trítij) — radioactive isotope of hydrogen
  • Catalan: triti — radioactive isotope of hydrogen
  • Chinese Cantonese: 氚 (cyun1) — radioactive isotope of hydrogen
  • Chinese Cantonese: 超重氫 /超重氢 (ciu1 zung6 hing1) — radioactive isotope of hydrogen
  • Chinese Mandarin: 氚 (chuān) — radioactive isotope of hydrogen
  • Chinese Mandarin: 超重氫 /超重氢 (chāozhòngqīng) — radioactive isotope of hydrogen
  • Dutch: tritium — radioactive isotope of hydrogen
  • Esperanto: tricio — radioactive isotope of hydrogen
  • Esperanto: tritio — radioactive isotope of hydrogen
  • Finnish: tritium — radioactive isotope of hydrogen
  • German: Tritium — radioactive isotope of hydrogen
  • Hungarian: trícium — radioactive isotope of hydrogen
  • Icelandic: þrívetni — radioactive isotope of hydrogen
  • Icelandic: ofurþungt vetni — radioactive isotope of hydrogen
  • Italian: trizio — radioactive isotope of hydrogen
  • Japanese: 三重水素 (sanjūsuiso) — radioactive isotope of hydrogen
  • Korean: 삼중수소 (samjungsuso) — radioactive isotope of hydrogen
  • Korean: 초중수소 (chojungsuso) — radioactive isotope of hydrogen
  • Korean: 트리튬 (teurityum) — radioactive isotope of hydrogen
  • Polish: tryt — radioactive isotope of hydrogen
  • Portuguese: trítio — radioactive isotope of hydrogen
  • Russian: три́тий (trítij) — radioactive isotope of hydrogen
  • Spanish: tritio — radioactive isotope of hydrogen
  • Swedish: tritium — radioactive isotope of hydrogen
  • Turkish: trityum — radioactive isotope of hydrogen