radioactive
adjective
ra·dio·ac·tive
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Definition of radioactive
1
: of, caused by, or exhibiting radioactivity
radioactive isotopes Radon is an odorless, colorless gas that arises naturally from the ground because of the decay of radioactive elements commonly found in rocks and many types of soil. In a chain of radioactive decay, uranium produces radium, which gives off radon, which in turn produces radioactive breakdown products that are harmful if inhaled.— Warren E. Leary
2
: so divisive or controversial as to require avoidance
He has been deemed radioactive by most charitable organizations … and organized competition, even local stuff, is largely closed off to him.— Asher Price Almost all women—and therefore men—use a form of birth control at some point in their lives, yet contraception is so politically and legally radioactive that legislators and pharmaceutical companies avoid funding it.— Karen Weise Subsequent polling data show that the quota issue is perhaps the most powerful one in our politics… A House Democratic aide says, "The quota issue is radioactive." The result has been nothing less than panic in the Democratic ranks.— Elizabeth Drew
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Examples of radioactive in a Sentence
Uranium and plutonium are radioactive.
Recent Examples on the Web
The northern Marshall Island atolls of Rongelap, Enewetak, Bikini and Utirik received the most radioactive fallout from the tests. — Susanne Rust, Los Angeles Times, "Radiation in parts of the Marshall Islands is far higher than Chernobyl, study says," 15 July 2019 Berezovsky was also a close associate of Alexander Litvinenko, a former spy who was killed with a radioactive poison in London in 2006. — Tom Winter, NBC News, "Nikolai Glushkov, who had links to Putin critic, dies in London," 13 Mar. 2018 An international team of researchers has traced an unusual 2017 radioactive release that blanketed a large part of Europe to Russia. — Washington Post, "Mysterious 2017 radioactive cloud over Europe originated in Russia, researchers say," 29 July 2019 The fear of abandonment is one reason that political disputes can become so radioactive. — Emily Esfahani Smith, National Review, "How to Protect Relationships in the Trump Era," 25 July 2019 Celebrity chef Guy Fieri jokingly offered to cater the event with radioactive ribs. — NBC News, "As Area 51 raid becomes a joke online, the U.S. Air Force issues a real warning," 18 July 2019 Going with the flow Unlike Earth’s erupting peaks and vents, Io’s volcanism isn’t powered by trapped heat left over from its formation or by the decay of naturally occurring radioactive compounds in its rocks. — Robin George Andrews, National Geographic, "This is our best look yet at the solar system's most volcanic object," 18 July 2019 Those reports say every mining operation around the world has needed some cleanup and are known to spread radioactive dust into the air that can seep into nearby areas. — Andrew Nicla, azcentral, "Bill to ban new uranium mining claims near the Grand Canyon passes House committee," 17 July 2019 Several hundred people currently live on Enewetak Island in the south of the atoll after a massive radioactive cleanup in 1980. — Helen Regan, CNN, "Parts of Marshall Islands are more radioactive than Chernobyl and Fukushima, study finds," 17 July 2019These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radioactive.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
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More Definitions for radioactive
radioactive
adjective
English Language Learners Definition of radioactive
: having or producing a powerful and dangerous form of energy (called radiation)
See the full definition for radioactive in the English Language Learners Dictionary
radioactive
adjective
ra·dio·ac·tive
| \ ˌrā-dē-ō-ˈak-tiv
\
\
Kids Definition of radioactive
: caused by or exhibiting radioactivity
a radioactive element
radioactive
adjective
ra·dio·ac·tive
| \ ˌrād-ē-ō-ˈak-tiv
\
\
Medical Definition of radioactive
: of, caused by, or exhibiting radioactivity
radioactive isotopes
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