radioactive
Americanadjective
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Physics, Chemistry. of, relating to, exhibiting, or caused by radioactivity.
A pressing issue in post-Soviet Russia is safe long-term storage of radioactive waste, from both military and civilian applications.
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relating to or being a person, topic, or matter that is likely to provoke intense negative reactions or disagreement.
The option of raising taxes to fund these expenditures is a politically radioactive approach that a majority of state policymakers have avoided.
adjective
Usage
What does radioactive mean? Radioactive describes something that exhibits or is caused by radioactivity. If something is radioactive, it emits radiation, which usually takes the form of electromagnetic waves or fast-moving elementary particles, such as protons or neutrons.While low doses of radiation are usually harmless, being exposed to large amounts of radiation will most likely kill you. For this reason, highly radioactive materials are often considered very dangerous and will only be handled by experts.Example: The radioactive waste produced by nuclear power plants can damage the environment.
Other Word Forms
- nonradioactive adjective
- radioactively adverb
- unradioactive adjective
Etymology
Origin of radioactive
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The nonrenewable gas is produced by radioactive decay deep under the earth and escapes into space once released.
From The Wall Street Journal • Mar. 31, 2026
Amundsen’s work is in keeping with the rest of the show, which fills two halls at the liberal arts school with visual and multimedia works that probe the persistence of radioactive materials.
From Los Angeles Times • Mar. 27, 2026
Herrera was certainly the less radioactive candidate of the two.
From Slate • Mar. 9, 2026
Tiny samples of radioactive material have twice been collected under a trial project using special tools, but full-fledged extractions are yet to take place.
From Barron's • Feb. 26, 2026
Seventeen crew members who had ridden in the helicopters had to be decontaminated, scrubbed from head to foot to remove any radioactive particles.
From "Meltdown" by Deirdre Langeland
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
