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

Tehran believes Israel and the U.S. introduced the Stuxnet computer virus in the early 2000s to target the centrifuges enriching uranium for Iran's nuclear program A series of sabotage attacks continued into the 2020s, as Israel sought to damage Iranian nuclear facilities. —Peter Kenyon, NPR, 12 Apr. 2024

Three other companies had already refused Mr. Compton’s request — to begin refining uranium for the development of the bomb. —Catie Edmondson, New York Times, 6 Apr. 2024

The junta’s statement made public concerns raised privately by the Biden administration that Nigerien leaders had agreed to supply uranium to Iran, crossing what Washington considers a red line. —Michael Birnbaum, Washington Post, 22 Mar. 2024

Researchers later found elevated uranium levels in the creek below. —The Arizona Republic, 10 Jan. 2024

Less than a year after Obama issued a presidential proclamation creating the monument on Dec. 28, 2016, then-President Trump undid it at the urging of the Utah state government, which wanted to leave the land open to uranium mining, oil drilling and cattle grazing. —Jack Herrera, Los Angeles Times, 3 Jan. 2024

Iran sped further than ever down the path of uranium enrichment, and its proxies, including the Houthis in Yemen and Hezbollah on Israel’s northern border, grew ever more powerful. —Anshel Pfeffer, The Atlantic, 27 Mar. 2024

The annual event has attracted at least 10 uranium firms, including Denison Mines Corp., Fission Uranium Corp. and IsoEnergy Ltd. As countries increasingly consider nuclear power to address climate change, demand for uranium is expected to skyrocket. —Jacob Lorinc, Fortune, 3 Mar. 2024

In the 1940s, uranium was first discovered on the Navajo Nation in the Carrizo Mountains near Cove. —The Arizona Republic, 6 Mar. 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