Skip to content
Vinony

lanthanum

noun

  1. chemical element with the atomic number of 57
L18240 on Wikidata ↗

Wiktionary

Pronunciation: /ˈlænθənəm/

noun

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

  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.
  2. An atom of this element.