Standard Lemma guide

radium

noun · verb · 4 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: /ˈɹeɪ.dɪ.əm/
  • General-American: rād'ēəm
  • General-American: /ˈɹeɪ.di.əm/
  • UK: Recorded audio is listed in the source snapshot.
  • General-American: Recorded audio is listed in the source snapshot.
  • CMU ARPABET: R EY1 D IY0 AH0 M Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

The chemical element (symbol Ra) with an atomic number of 88. It is a soft, shiny and silvery radioactive alkaline earth metal.

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

2

noun

Meaning 2

A type of cloth woven from silk or synthetic yarn, often with a shiny appearance.

Definition source: English Wiktionary via Wiktextract

Usage: countable, dated, uncountable

Topics: business, manufacturing, textiles

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

verb

Meaning 3

To treat (a tumour, etc.) with radium.

Definition source: English Wiktionary via Wiktextract

Usage: ambitransitive, obsolete

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: radiumize

Antonyms: none provided

4

noun

Meaning 4

an intensely radioactive metallic element that occurs in minute amounts in uranium ores

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: Ra, atomic number 88

Antonyms: none provided

Broader terms: metallic element, metal

History

Etymology

Etymology tree Latin radiusder. French radio- Proto-Indo-European *h2eǵ- Proto-Indo-European *-eti Proto-Indo-European *h2éǵeti Proto-Italic *agō Latin agō Proto-Indo-European *-wós Proto-Indo-European *-iHwósder. Latin -īvus ▲ Ancient Greek ἐνεργητῐκός (energētĭkós)sl. Latin āctīvusbor. Old French actif French actif French radio(actif) Proto-Indo-European *-(i)yós Proto-Italic *-ijos Proto-Italic *-ios Old Latin -ios Latin -ius Latin -ium French radiumbor. English radium Borrowed from French radium, from rad(ioactif) (“radioactive”) + -ium (suffix used to form the names of metallic elements).

Across languages

Translations

55 source translations are retained for this English entry.

  • Afrikaans: radium — chemical element with an atomic number of 88
  • Arabic: رَادِيُوم (rādiyūm) — chemical element with an atomic number of 88
  • Armenian: ռադիում (ṙadium) — chemical element with an atomic number of 88
  • Asturian: radiu — chemical element with an atomic number of 88
  • Breton: radiom — chemical element with an atomic number of 88
  • Bulgarian: радий (radij) — chemical element with an atomic number of 88
  • Burmese: ရေဒီယမ် (rediyam) — chemical element with an atomic number of 88
  • Catalan: radi — chemical element with an atomic number of 88
  • Chinese Cantonese: 鐳 /镭 (leoi4) — chemical element with an atomic number of 88
  • Chinese Mandarin: 鐳 /镭 (léi) — chemical element with an atomic number of 88
  • Czech: radium — chemical element with an atomic number of 88
  • Czech: rádium — chemical element with an atomic number of 88
  • Dutch: radium — chemical element with an atomic number of 88
  • Esperanto: radiumo — chemical element with an atomic number of 88
  • Estonian: raadium — chemical element with an atomic number of 88
  • Finnish: radium — chemical element with an atomic number of 88
  • French: radium — chemical element with an atomic number of 88
  • Galician: radio — chemical element with an atomic number of 88
  • Georgian: რადიუმი (radiumi) — chemical element with an atomic number of 88
  • German: Radium — chemical element with an atomic number of 88
  • Greek: ράδιο (rádio) — chemical element with an atomic number of 88
  • Hebrew: רדיום (radiyum) — chemical element with an atomic number of 88
  • Hindi: तेजातु (tejātu) — chemical element with an atomic number of 88
  • Hindi: रेडियम (reḍiyam) — chemical element with an atomic number of 88
  • Hungarian: rádium — chemical element with an atomic number of 88
  • Italian: radio — chemical element with an atomic number of 88
  • Japanese: ラジウム (rajiumu) — chemical element with an atomic number of 88
  • Japanese: ラディウム (radiumu) — chemical element with an atomic number of 88
  • Khmer: រ៉ាដ្យូម (raadyoum) — chemical element with an atomic number of 88
  • Korean: 라듐 (radyum) — chemical element with an atomic number of 88
  • Latvian: rādijs — chemical element with an atomic number of 88
  • Lithuanian: radis — chemical element with an atomic number of 88
  • Māori: konuruke — chemical element with an atomic number of 88
  • Norwegian Bokmål: radium — chemical element with an atomic number of 88
  • Norwegian Nynorsk: radium — chemical element with an atomic number of 88
  • Occitan: radi — chemical element with an atomic number of 88
  • Persian: رادیوم (râdiyom) — chemical element with an atomic number of 88
  • Polish: rad — chemical element with an atomic number of 88
  • Portuguese: rádio — chemical element with an atomic number of 88
  • Romanian: radiu — chemical element with an atomic number of 88
  • Russian: ра́дий (rádij) — chemical element with an atomic number of 88
  • Serbo-Croatian: ра̑дӣј — chemical element with an atomic number of 88
  • Serbo-Croatian: rȃdīj — chemical element with an atomic number of 88
  • Spanish: radio — chemical element with an atomic number of 88
  • Spanish: radium — chemical element with an atomic number of 88
  • Spanish: rádium — chemical element with an atomic number of 88
  • Swedish: radium — chemical element with an atomic number of 88
  • Tamil: கருகன் (karukaṉ) — chemical element with an atomic number of 88
  • Thai: เรเดียม (ree-dîiam) — chemical element with an atomic number of 88
  • Turkish: radyum — chemical element with an atomic number of 88
  • Ukrainian: ра́дій (rádij) — chemical element with an atomic number of 88
  • Uyghur: رادىي (radiy) — chemical element with an atomic number of 88
  • Uzbek: radiy — chemical element with an atomic number of 88
  • Vietnamese: rađi — chemical element with an atomic number of 88
  • Volapük: radin — chemical element with an atomic number of 88
Real reading context

radium in complete knowledge articles