radioactive
adjective
ra·dio·ac·tive
ˌrā-dē-ō-ˈak-tiv 
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
Warren E. Leary2
: 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
Asher PriceAlmost 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
Karen WeiseSubsequent 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
Elizabeth Drew
radioactively
adverb
Plutonium is the only one of these transuranic elements that can exist a fair amount of time before radioactively decaying into lighter elements.
—James Kaler
James Kaler
Examples of radioactive in a Sentence
Uranium and plutonium are radioactive.
Recent Examples on the Web
And despite decades of trying, the department has yet to fully clean up and dismantle the oozing, disintegrating tanks of highly radioactive wastes left over from plutonium processing at Hanford.
—Michael Riordan, Scientific American, 31 Jan. 2025
The anti-commandeering rule was first articulated in 1992 when the Supreme Court ruled in New York v. United States that the federal government could not force a state to take control of radioactive waste generated within its boundaries.
—Claire B. Wofford, The Conversation, 27 Jan. 2025
Columnist Teri Sforza writes that a demonstration project aims to showcase the safety of transporting highly radioactive waste.
—Teri Sforza, Orange County Register, 19 Jan. 2025
Radon — a radioactive gas found in some homes, particularly in the Midwest — is the leading cause of lung cancer in people who have never smoked.
—Aria Bendix, NBC News, 16 Jan. 2025
See all Example Sentences for radioactive 
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Michael Riordan, Scientific American, 31 Jan. 2025
The anti-commandeering rule was first articulated in 1992 when the Supreme Court ruled in New York v. United States that the federal government could not force a state to take control of radioactive waste generated within its boundaries.
—Claire B. Wofford, The Conversation, 27 Jan. 2025
Columnist Teri Sforza writes that a demonstration project aims to showcase the safety of transporting highly radioactive waste.
—Teri Sforza, Orange County Register, 19 Jan. 2025
Radon — a radioactive gas found in some homes, particularly in the Midwest — is the leading cause of lung cancer in people who have never smoked.
—Aria Bendix, NBC News, 16 Jan. 2025
See all Example Sentences for radioactive
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Cite this Entry
“Radioactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radioactive. Accessed 8 Feb. 2025.
Copy CitationKids Definition
radioactive
adjective
ra·dio·ac·tive
ˌrād-ē-ō-ˈak-tiv
: of, caused by, or exhibiting radioactivity
radioactively
adverb
Medical Definition
radioactive
adjective
ra·dio·ac·tive
ˌrād-ē-ō-ˈak-tiv
: of, caused by, or exhibiting radioactivity
radioactive isotopes
radioactively
adverb
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