Standard Lemma guide

protactinium

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

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  • UK: /ˌpɹəʊ.tækˈtɪn.i.əm/
  • US: prō"tăktĭ'nēəm
  • US: /ˌpɹoʊ.tækˈtɪn.i.əm/
  • US: Recorded audio is listed in the source snapshot.
  • General-American: Recorded audio is listed in the source snapshot.

1

noun

Meaning 1

A chemical element (symbol Pa) with atomic number 91. A dense, silvery-gray actinide metal.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: protoactinium, Pa, atomic number 91

Antonyms: none provided

Broader terms: metallic element, metal

History

Etymology

Etymology tree Proto-Indo-European *per-der.? Proto-Indo-European *per-der.? Proto-Indo-European *pér Proto-Indo-European *-o Proto-Indo-European *próder. Ancient Greek πρό (pró) Ancient Greek -ᾰτος (-ătos) Ancient Greek πρῶτος (prôtos) Ancient Greek πρωτο- (prōto-)lbor. English proto- English actinium English protactinium From proto- + actinium.

Across languages

Translations

70 source translations are retained for this English entry.

  • Afrikaans: protaktinium — chemical element
  • Albanian: protaktin — chemical element
  • Arabic: بُرُوتَكْتِينِيُوم (burūtaktīniyūm) — chemical element
  • Armenian: պրոտակտինիում (protaktinium) — chemical element
  • Asturian: protactiniu — chemical element
  • Basque: protaktinioa — chemical element
  • Belarusian: пратакты́ній (prataktýnij) — chemical element
  • Breton: protaktiniom — chemical element
  • Bulgarian: протакти́ний (protaktínij) — chemical element
  • Catalan: protactini — chemical element
  • Chinese Mandarin: 鏷 /镤 (pú) — chemical element
  • Cornish: protoactynyum — chemical element
  • Czech: protaktinium — chemical element
  • Danish: protactinium — chemical element
  • Dutch: protactinium — chemical element
  • Esperanto: protaktinio — chemical element
  • Estonian: protaktiinium — chemical element
  • Faroese: protaktinium — chemical element
  • Finnish: protaktinium — chemical element
  • French: protactinium — chemical element
  • West-Frisian: protactinium — chemical element
  • Friulian: protoatini — chemical element
  • Galician: protactinio — chemical element
  • Georgian: პროტაქტინიუმი (ṗroṭakṭiniumi) — chemical element
  • German: Protactinium — chemical element
  • Greek: πρωτακτίνιο (protaktínio) — chemical element
  • Hebrew: פרוטקטיניום (protaktínyum) — chemical element
  • Hindi: प्रैजातु (praijātu) — chemical element
  • Hungarian: protaktínium — chemical element
  • Icelandic: protaktín — chemical element
  • Irish: prótachtainiam — chemical element
  • Italian: protoattinio — chemical element
  • Japanese: プロトアクチニウム (purotoakuchiniumu) — chemical element
  • Kashubian: protaktin — chemical element
  • Kazakh: протактиний (protaktinii) — chemical element
  • Khmer: ប្រូតាក់ទីញ៉ូម (protaktinhum) — chemical element
  • Korean: 프로트악티늄 (peuroteuaktinyum) — chemical element
  • Latin: protactinium — chemical element
  • Latvian: protaktīnijs — chemical element
  • Lithuanian: protaktinis — chemical element
  • Luxembourgish: Protaktinium — chemical element
  • Macedonian: протактиниум (protaktinium) — chemical element
  • Malay: protaktinium — chemical element
  • Maltese: protaktinjum — chemical element
  • Manx: protaghtinnium — chemical element
  • Mongolian: протактини (protaktini) — chemical element
  • Norwegian: protactinium — chemical element
  • Polish: protaktyn — chemical element
  • Portuguese: protactínio — chemical element
  • Romanian: protactiniu — chemical element
  • Russian: протакти́ний (protaktínij) — chemical element
  • Scottish Gaelic: pròtactainiam — chemical element
  • Serbo-Croatian: протоактиниj — chemical element
  • Serbo-Croatian: протоактиниjум — chemical element
  • Serbo-Croatian: protaktinij — chemical element
  • Serbo-Croatian: protaktinijum — chemical element
  • Slovak: protaktínium — chemical element
  • Slovene: protaktinij — chemical element
  • Spanish: protactinio — chemical element
  • Swedish: protaktinium — chemical element
  • Tajik: протактиний (protaktiniy) — chemical element
  • Tamil: புரொட்டக்டினியம் (puroṭṭakṭiṉiyam) — chemical element
  • Thai: โพรแทกทิเนียม (proo-tɛ́k-tí-nîiam) — chemical element
  • Turkish: protaktinyum — chemical element
  • Ukrainian: протакти́ній (protaktýnij) — chemical element
  • Uzbek: protaktiniy — chemical element
  • Uzbek: протактиний (protaktiniy) — chemical element
  • Vietnamese: protactini — chemical element
  • Volapük: protaktinin — chemical element
  • Welsh: protoactiniwm — chemical element