uranium
noun
ura·ni·um
yu̇-ˈrā-nē-əm 
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
President Donald Trump's administration seeks to halt Iran's uranium enrichment, emphasizing diplomatic negotiations over military action.
—
Russel Honoré, Newsweek, 5 Mar. 2025
Driving the news: Ukraine has deposits of graphite, lithium, rare earths, uranium, and more.
—Ben Geman, Axios, 28 Feb. 2025
The stock of uranium enriched to up to 60% fissile purity, close to the roughly 90% of bomb grade, has been a long-standing concern for Western powers, which say there is no civil justification for enriching uranium to such a high level.
—Reuters, NBC News, 27 Feb. 2025
Under the original 2015 nuclear deal, Iran was allowed to enrich uranium only up to 3.67% purity and maintain a stockpile of uranium of almost 700 pounds.
—Stephanie Liechtenstein The Associated Press, arkansasonline.com, 27 Feb. 2025
See All Example Sentences for uranium
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Russel Honoré, Newsweek, 5 Mar. 2025
Driving the news: Ukraine has deposits of graphite, lithium, rare earths, uranium, and more.
—Ben Geman, Axios, 28 Feb. 2025
The stock of uranium enriched to up to 60% fissile purity, close to the roughly 90% of bomb grade, has been a long-standing concern for Western powers, which say there is no civil justification for enriching uranium to such a high level.
—Reuters, NBC News, 27 Feb. 2025
Under the original 2015 nuclear deal, Iran was allowed to enrich uranium only up to 3.67% purity and maintain a stockpile of uranium of almost 700 pounds.
—Stephanie Liechtenstein The Associated Press, arkansasonline.com, 27 Feb. 2025
See All Example Sentences for uranium
Cite this Entry
“Uranium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/uranium. Accessed 12 Mar. 2025.
Copy CitationKids Definition
uranium
noun
ura·ni·um
yȯ-ˈrā-nē-əm
: 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
: 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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