radioactive
4 synonyms and 1 antonym for radioactive, grouped by meaning and by how common each one is.
Adjective — Giving off radiation from the decay of unstable atomic nuclei.
Synonyms
Less common
Still standard English, but they carry more weight.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
Antonyms
nonradioactive
How to use radioactive
The word patterns that sound natural to a native speaker.
radioactive material
radioactive decay
politically radioactive
Etymology
Coined by Pierre and Marie Curie in 1898 as the French radio-actif, from "radio-" plus "active".
Full origin of radioactive →Frequently asked questions
What does “radioactive” mean?
The word “radioactive” means giving off radiation from the decay of unstable atomic nuclei. In plain terms, emitting radiation from unstable atoms, or figuratively, too toxic or controversial to touch.
How do you pronounce “radioactive”?
“Radioactive” is pronounced ray-dee-oh-AKTIHV (/ˌɹeɪdioʊˈæktɪv/ in IPA).
How do you use “radioactive” in a sentence?
Here is “radioactive” used in a sentence: “Radioactive waste must be stored safely for thousands of years.”
What part of speech is “radioactive”?
“Radioactive” is an adjective.
Where does the word “radioactive” come from?
The word “radioactive” dates back to around 1898 and comes from French. Coined by Pierre and Marie Curie in 1898 as the French radio-actif, from "radio-" plus "active".
Is “radioactive” a common word?
“Radioactive” is a fairly common word in modern English.
How many meanings does “radioactive” have?
“Radioactive” has 2 distinct senses listed in this dictionary. The most common is: giving off radiation from the decay of unstable atomic nuclei.
What is the difference between radioactive and nuclear?
Radioactive describes a material that gives off radiation from the decay of unstable atomic nuclei, while nuclear refers more broadly to anything involving atomic nuclei, including reactions that may not release radiation on their own. A substance can be nuclear-related without necessarily being radioactive.
What makes something radioactive?
A material becomes radioactive when it contains unstable atomic nuclei that break down, or decay, releasing energy in the form of radiation. This decay continues until the unstable atoms become stable.
Why do people call a topic radioactive?
Figuratively, calling a topic or person radioactive means it is so controversial or toxic that others avoid associating with it, much as people keep their distance from harmful radiation.
