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 shipyard processed approximately 8,000 cubic feet of radioactive solid waste from nuclear submarines between 2013 and 2017, according to a recent report from the Energy Department. — Washington Post, "Projects defunded for Trump’s border wall include military buildings with ‘life safety violations’ and hazmat concerns," 6 Sep. 2019 Millions of tons of heavy metals and chemical contaminants, along with thousands of containers of radioactive waste, were purposely thrown into the ocean. — Jenny Howard, National Geographic, "Marine pollution, explained," 2 Aug. 2019 In 1992, the Supreme Court heard New York v. United States, a dispute between Albany and Washington over a federal law that required states to take legal responsibility for radioactive waste in certain circumstances. — Matt Ford, The New Republic, "Make the Guarantee Clause Great Again," 17 July 2019 In 2008, Russia ordered the council to close all its offices except the Moscow headquarters as part of retaliation for the U.K.’s expulsion of diplomats over the radioactive poisoning of former security-service officer Alexander Litvinenko in 2006. — Anthony Halpin, Bloomberg.com, "Russia Orders the Expulsion of 23 British Diplomats in Retaliation," 17 Mar. 2018 Berezovsky was a close friend of former Russian spy Alexander Litvinenko, who died from radioactive poisoning in 2006. — Corky Siemaszko, NBC News, "Friend of dead Putin critic was strangled, British police say," 16 Mar. 2018 Speculation mounted Wednesday that Russia was behind the attack, given the strong similarities to the case of former Russian intelligence officer Alexander Litvinenko, who died from radioactive polonium-210 poisoning in London in 2006. — Christina Boyle, latimes.com, "Scotland Yard says nerve agent poisoned former Russian spy and his daughter," 7 Mar. 2018 Nothing good can last—and in the case of carbon-14, a radioactive isotope found in Earth’s atmosphere, that’s great news for archaeologists. — Erin Blakemore, National Geographic, "Radiocarbon helps date ancient objects—but it's not perfect," 12 July 2019 Under a 1982 law, the federal government was supposed to pick up the nuclear industry’s waste and put it in a safe place underground for the next few hundreds of thousands of years (the half-life of some radioactive isotopes). — Eric Niiler, WIRED, "Senators Try—Again—to Solve the Nuclear Waste Debacle," 28 June 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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