uranium

play

noun, often attributive ura·ni·um \ yu̇-ˈrā-nē-əm \

Definition of uranium

: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

See uranium defined for English-language learners

See uranium defined for kids

Recent Examples of uranium from the Web

Joe Wilson was the former chief of mission at the US Embassy in Iraq and had previously investigated the uranium allegations at the behest of the CIA.

— david kravets, Ars Technica, "Here’s a way to silence Trump on Twitter: Buy the microblogging service," 23 Aug. 2017
The Iranians might produce enriched uranium—but that required using centrifuges.

— michael lewis, The Hive, "Why the Scariest Nuclear Threat May Be Coming from Inside the White House," 2 Aug. 2017
Russians are chattering about the possibility of cutting uranium or titanium exports to the U.S., expelling major U.S. firms, or going into high diplomatic gear to block U.S. initiatives on North Korea and other priorities.

— heather hulburt, Daily Intelligencer, "How Will Trump Handle Putin’s Disappointment?," 31 July 2017
In one controversial deal, the U.S. government approved sales of a large amount of North American uranium deposits to Russian interests.

— victor davis hanson, National Review, "Putin’s Playthings," 20 July 2017
Journalist Peter Schweitzer revealed in his book Clinton Cash that State had helped move along an infamous deal that granted the Russians control of more than 20 percent of the uranium production here in the United States.

— john fund, National Review, "Not All Foreign-Influence Scandals Are Created Equal," 16 July 2017
In 2015 the Obama administration negotiated limits on uranium enrichment and, in exchange, helped lift certain sanctions placed against Iran.

— j. weston phippen, The Atlantic, "Iran Signs a $5 Billion Energy Deal With France's Total," 3 July 2017
But the mines are open again, this time as a source of uranium, under Soviet supervision.

— weston williams, The Christian Science Monitor, "'History of a Disappearance' tells the story of a once vibrant Polish town," 1 July 2017
According to the complaint and his online biography, Snelling obtained a doctoral degree in geology from the University of Sydney in 1982 and began his career by studying the Koongarra uranium deposit in Australia's Northern Territory.

— amanda reilly, Science | AAAS, "Update: Creationist geologist wins permit to collect rocks in Grand Canyon after lawsuit," 30 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'uranium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of uranium

New Latin, from Uranus

NEW! Time Traveler

First Known Use: circa 1797

See Words from the same year

URANIUM Defined for English Language Learners

uranium

play

noun

Definition of uranium for English Language Learners

: a radioactive element that is used to make nuclear energy and nuclear weapons

URANIUM Defined for Kids

uranium

play

noun ura·ni·um \ yu̇-ˈrā-nē-əm \

Definition of uranium for Students

:a radioactive metallic chemical element used as a source of atomic energy

Medical Dictionary

uranium

play

noun ura·ni·um \ yu̇-ˈrā-nē-əm \

medical Definition of uranium

: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

Learn More about uranium

See words that rhyme with uranium Spanish Central: Translation of uranium Nglish: Translation of uranium for Spanish speakers Britannica English: Translation of uranium for Arabic speakers Britannica.com: Encyclopedia article about uranium

Seen and Heard

What made you want to look up uranium? Please tell us where you read or heard it (including the quote, if possible).

show

uranium

Definition of uranium

Recent Examples of uranium from the Web

Origin and Etymology of uranium

URANIUM Defined for English Language Learners

uranium

Definition of uranium for English Language Learners

URANIUM Defined for Kids

uranium

Definition of uranium for Students

Medical Dictionary

uranium

medical Definition of uranium

Learn More about uranium

Seen and Heard

WORD OF THE DAY

yeasty

BROWSE DICTIONARY

Test Your Vocabulary

Words at Play

Breathing Life Into 'Inspire'

Let's Talk 'Tea'

8 Words and Phrases from Boxing and Wrestling

The Ambiguity of Pushing 'Up' and 'Back'

Ask the Editors

Words of the Year: 1066

How Often Is 'Biweekly'?

Irregardless

Weird Plurals

Word Games

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

Challenging Vocabulary Quiz Returns!

Spell It

SCRABBLE® Sprint

Breathing Life Into 'Inspire'

Trending: Kim Jong Un: Trump a 'Dotard'

These Are Fighting Words

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

Words of the Year: 1066

uranium

Definition of uranium

Explore M-W

Recent Examples of uranium from the Web

Origin and Etymology of uranium

URANIUM Defined for English Language Learners

uranium

Definition of uranium for English Language Learners

URANIUM Defined for Kids

uranium

Definition of uranium for Students

Medical Dictionary

uranium

medical Definition of uranium

Learn More about uranium

Seen and Heard

Love words? Need even more definitions?

Love words? Need even more definitions?

Words at Play

Ask the Editors

Word Games

Breathing Life Into 'Inspire'

Trending: Kim Jong Un: Trump a 'Dotard'

These Are Fighting Words

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

Words of the Year: 1066