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

Economic pressure mounts as Iran's currency, the rial, hovers near record lows due to international sanctions linked to its nuclear ambitions, which involve enriching uranium closer to weapons-grade levels. —Gordon G. Chang, Newsweek, 31 Oct. 2024

One issue important on the Navajo Nation is uranium mining, especially as extraction has begun at the Pinyon Plain Mine near the Grand Canyon. —Arlyssa D. Becenti, The Arizona Republic, 26 Oct. 2024

The West and Israel should be mindful over the apparent change in tempo of Iran’s uranium enrichment and be petrified of losing the wider war of non proliferation in a region unable to step back from the brink. —Nick Paton Walsh, CNN, 28 Sep. 2024

The Niagara site from 1944 to 1952 received radioactive wastes associated with uranium extraction for the Manhattan Project's development of atomic bombs during and just after World War II. —Keith Matheny, Detroit Free Press, 18 Sep. 2024

Word History

Etymology

New Latin, from Uranus

First Known Use

1790, 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