thulium

 
Pronunciation: /ˈθ(j)uːlɪəm/

noun

[mass noun]
  • the chemical element of atomic number 69, a soft silvery-white metal of the lanthanide series. (Symbol: Tm)

Origin:

late 19th century: modern Latin, from Latin Thule (see Thule (sense 1)), from Greek Thoulē, of unknown origin