uranium

noun

ura·​ni·​um yu̇-ˈrā-nē-əm How to pronounce uranium (audio)
often attributive
: a silvery heavy radioactive polyvalent metallic element that is found especially in uraninite and exists naturally as a mixture of mostly nonfissionable isotopes see Chemical Elements Table

Examples of uranium in a Sentence

Recent Examples on the Web
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Prince Abdulaziz bin Salman, Saudi Arabia's energy minister, said in recent days that Riyadh plans to enrich and sell uranium. Ellie Cook, Newsweek, 19 Jan. 2025 Greenland is also known to have significant lithium, hafnium, uranium and gold deposits. Sam Meredith, CNBC, 17 Jan. 2025 The site is mined for gold and uranium, a radioactive metal. Katie Hunt, CNN, 17 Jan. 2025 The issue was put to rest in 2021 when Greenland’s parliament banned all uranium mining, killing further development of Kvanefjeld for the time being. Scott L. Montgomery, The Conversation, 14 Jan. 2025 See all Example Sentences for uranium 

Word History

Etymology

New Latin, from Uranus

First Known Use

1790, in the meaning defined above

Time Traveler
The first known use of uranium was in 1790

Dictionary Entries Near uranium

Cite this Entry

“Uranium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/uranium. Accessed 28 Jan. 2025.

Kids Definition

uranium

noun
ura·​ni·​um yȯ-ˈrā-nē-əm How to pronounce uranium (audio)
: a silvery heavy radioactive metallic element see element
Etymology

scientific Latin; named for the planet Uranus, from Latin Uranus, name of the god of heaven

Word Origin
The ancient Greek word ouranos meant "sky, heaven." It was fitting, then, for the Greeks to name their god of heaven Ouranos and their muse of astronomy Ourania. In Latin these names became Uranus and Urania. Uranus was the father of the god Saturn and the grandfather of Jupiter. In 1781 the English astronomer Sir William Herschel discovered by telescope the seventh planet of our solar system. It was the custom to name planets after Roman gods. Following this custom, the German astronomer Johann Bode suggested the name Uranus for this planet. It seemed a good idea since the fifth planet was called Jupiter and the sixth was Saturn. Eight years after the discovery of Uranus, the German chemist Martin Klaproth discovered a new element. He called it uranium after the new planet Uranus.

Medical Definition

uranium

noun
ura·​ni·​um yu̇-ˈrā-nē-əm How to pronounce uranium (audio)
: a silvery heavy radioactive polyvalent metallic element that is found especially in pitchblende and uraninite and exists naturally as a mixture of three isotopes of mass number 234, 235, and 238 in the proportions of 0.006 percent, 0.71 percent, and 99.28 percent respectively
symbol U
see Chemical Elements Table

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