lan·tha·num
noun/ˈlænθənəm/
/ˈlænθənəm/
[uncountable] (symbol La)
- a chemical element. Lanthanum is a silver-white metal.
镧 Word Originmid 19th cent.: from Greek lanthanein ‘escape notice’ (because for a long time it was undetected in cerium oxide) + -um.