Meaning of thulium

thu•li•um

Pronunciation: (th'lē-um), [key]
— n. Chem.
  1. a rare-earth metallic element found in the minerals euxenite, gadolinite, etc. Symbol: Tm; at. wt.: 168.934; at. no.: 69; sp. gr.: 9.32.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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