Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “radioactivity”

radioactivity

noun [U] uk   /ˌreɪ.di.əʊ.ækˈtɪv.ɪ.ti/ us    /-oʊ.ækˈtɪv.ə.t̬i/
the quality that some atoms have of producing energy, which can be very harmful to healthRadiation and radioactivity the energy produced by atoms in this way: A dangerous amount of radioactivity was released into the environment last month.Radiation and radioactivity
(Definition of radioactivity from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of radioactivity?
Add Cambridge dictionaries to your browser to your website

Definitions of “radioactivity” in other dictionaries

Word of the Day

microbrewery

a small company that makes beer, usually using traditional methods, and often has a restaurant where its beer is served

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More