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Definition of radioactive

radioactive

/ˌreɪdioʊˈæktɪv/
ra · di · o · ac · tive
Adverb:radioactively
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radioactive Lexical Profile

radioactive Game Scores & Validity

• adjective

1

Emitting or relating to the emission of ionizing radiation or subatomic particles caused by the spontaneous disintegration of atomic nuclei.

Example

"Technicians wore specialized protective suits before handling the radioactive waste at the facility."

2

So controversial, tainted, or politically dangerous that people avoid any association with it.

Example

"After the financial scandal broke, the disgraced executive became politically radioactive to his former allies."

Synonyms
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Antonyms
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• Rhymes for radioactive

• Nearby Words

radicalness
radicchio
radio
radioactive
radioactively
radioactivity
radiobroadcaster

Word Origin & Etymology

Coined in French as 'radio-actif' in 1898 by physicists Marie and Pierre Curie, combining 'radio-' (from Latin 'radius', meaning 'ray') and 'actif' ('active') to describe elements that spontaneously emit radiation.

Cite this Entry

Wordmom. (2026). Definition of Radioactive. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/radioactive
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