Definition of radioactivity in English:

Share this entry


Pronunciation: /ˌreədēōakˈtivədē/


1The emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei.
Example sentences
  • Early studies of radioactivity revealed that certain atomic nuclei were naturally radioactive.
  • They may also interact with nonmedical regulations, such as limits on electromagnetic emissions or radioactivity.
  • What makes dirty bombs particularly troublesome is that radioactivity, like fire, is something we deal with on a daily basis.
1.1Radioactive substances, or the radiation emitted by these.
Example sentences
  • Small amounts of radioactivity escaped into the atmosphere.
  • The lack of safeguards is leaving thousands of children across central Scotland at risk of thyroid cancer following an escape of radioactivity.
  • They are comparing sediment taken from the Humber estuary - unpolluted by radioactivity - with other samples which contain the substance.

For editors and proofreaders

Syllabification: ra·di·o·ac·tiv·i·ty

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.