: a metallic chemical element of the rare-earth group that has few practical applications but is sometimes used as a catalyst in cracking and as a radiation source for treatment of certain cancers see Chemical Elements Table
Example Sentences
Recent Examples on the WebThe least abundant of these, thulium (Tm) and lutetium (Lu) are 200 times more abundant than gold. Willy Shih, Forbes, 24 Feb. 2021
Word History
Etymology
New Latin, from Latin Lutetia, ancient name of Paris