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

Energy Fuels contends that uranium mining in that location would not compromise the Grand Canyon watershed. —Trilce Estrada Olvera, The Arizona Republic, 5 July 2024

Tehran knew inspectors would see and report the December change, which strongly suggests its leaders wanted to communicate that the possibility of producing weapons-grade uranium was back on the table. —Eric Brewer, Foreign Affairs, 25 June 2024

Critically, the Energy Department has been working to supercharge the production of the enriched uranium needed to fuel advanced reactors. —Robert Gebelhoff, Washington Post, 25 June 2024

As a county physician in the town of Schwarzenberg, near Dresden, Walther investigated the mysterious lung disease afflicting workers in nearby uranium mines. —Corrado Nai, Smithsonian Magazine, 25 June 2024

Word History

Etymology

New Latin, from Uranus

First Known Use

circa 1797, in the meaning defined above

Phrases Containing uranium

• uranium hexafluoride

Kids 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