Found 2 items, similar to Thulium.
English → English (WordNet) Definition: thulium thulium n : a soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime [syn: Tm, atomic number 69]
English → English (gcide) Definition: Thulium Thulium \Thu"li*um\, n. [NL. See Thule.] (Chem.) A rare metallic element of uncertain properties and identity, said to have been found in the mineral gadolinite. [1913 Webster] [1913 Webster]