Lanthanum

//ˈlænθənəm// noun

noun ·Uncommon ·Advanced level

Definitions

Noun
  1. 1
    A chemical element (symbol La) with an atomic number of 57: a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. uncountable
  2. 2
    a white soft metallic element that tarnishes readily; occurs in rare earth minerals and is usually classified as a rare earth wordnet
  3. 3
    An atom of this element. countable

Synonyms

All synonyms
laatomic number 57ausoniumgoldironlead

Etymology

From Ancient Greek λανθάνω (lanthánō, “to escape notice”) + -um (“a chemical element”), because it had gone long undetected in mineral ores.

Related phrases

lanthanum carbonatelanthanum chloridelanthanum glasslanthanum nitratelanthanum oxidelanthanum oxybromidelanthanum sesquioxideatomic numberrare earth

More for "lanthanum"

SynonymsSentencesPronunciationTranslate

Next best steps

Find stronger synonymsSee usage examplesCheck pronunciationBrowse writing guides

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.