thorium

noun

tho·​ri·​um ˈthȯr-ē-əm How to pronounce thorium (audio)
: a radioactive metallic element that is obtained especially from monazite and is usually associated with rare earths see Chemical Elements Table

Examples of thorium in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
But first, researchers needed to pinpoint the exact amount of energy capable of exciting the thorium nucleus. Shi En Kim, Smithsonian Magazine, 23 Sep. 2024 But making all that possible will require cutting down the uncertainty of thorium’s transition by at least another tenfold. Shi En Kim, Smithsonian Magazine, 23 Sep. 2024 The team trained the laser comb onto thorium atoms embedded in calcium fluoride grains and scanned for the telltale frequency. Shi En Kim, Smithsonian Magazine, 23 Sep. 2024 The thorium nuclear state’s energy is far more sensitive to variations in the fundamental constants than that of any atomic state. Quanta Magazine, 4 Sep. 2024 See all Example Sentences for thorium 

Word History

Etymology

New Latin, from Old Norse Thōrr Thor

First Known Use

1832, in the meaning defined above

Time Traveler
The first known use of thorium was in 1832

Dictionary Entries Near thorium

Cite this Entry

“Thorium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thorium. Accessed 28 Nov. 2024.

Kids Definition

thorium

noun
tho·​ri·​um ˈthōr-ē-əm How to pronounce thorium (audio)
ˈthȯr-
: a radioactive metallic element see element

Medical Definition

thorium

noun
tho·​ri·​um ˈthōr-ē-əm, ˈthȯr- How to pronounce thorium (audio)
: a radioactive metallic element that occurs combined in minerals and is usually associated with rare earths
symbol Th
see Chemical Elements Table

More from Merriam-Webster on thorium

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