Medical Dictionary

radioactivity

noun ra·dio·ac·tiv·i·ty \-ak-ˈtiv-ət-ē\
plural ra·dio·ac·tiv·i·ties

Medical Definition of RADIOACTIVITY

:  the property possessed by some elements (as uranium) or isotopes (as carbon 14) of spontaneously emitting energetic particles (as electrons or alpha particles) by the disintegration of their atomic nuclei

Browse

May 24, 2015
erudite Hear it
learned or pedantic
Take a 3-minute break and test your skills!
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears