thu·​li·​um | \ ˈthü-lē-əm How to pronounce thulium (audio) , ˈthyü- \

Definition of thulium

: a soft silvery metallic element of the rare-earth group — see Chemical Elements Table

Examples of thulium in a Sentence

Recent Examples on the Web The least abundant of these, thulium (Tm) and lutetium (Lu) are 200 times more abundant than gold. Willy Shih, Forbes, 24 Feb. 2021 The 794 nm photon interacts with a lithium-niobate crystal doped with thulium, so that the photon’s state becomes stored in the crystal. Anil Ananthaswamy, Scientific American, 19 June 2019 Electronic shielding by closed shells in thulium compounds. Spencer Reiss, WIRED, 1 May 2004

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thulium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of thulium

1879, in the meaning defined above

History and Etymology for thulium

New Latin, from Latin Thule

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The first known use of thulium was in 1879

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Dictionary Entries Near thulium

thulite pink



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Cite this Entry

“Thulium.” Dictionary, Merriam-Webster, Accessed 26 Sep. 2021.

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More Definitions for thulium


thu·​li·​um | \ ˈth(y)ü-lē-əm How to pronounce thulium (audio) \

Medical Definition of thulium

: a trivalent metallic element of the rare-earth group symbol Tm — see Chemical Elements Table

More from Merriam-Webster on thulium Encyclopedia article about thulium


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