Etymology
Advertisement

radioactive (adj.)

1898, of an atomic nucleus, "capable of spontaneous nuclear decay releasing ionizing emissions," from French radio-actif, coined by Pierre and Marie Curie from radio-, combining form of Latin radius "ray" (see radius) + actif "active" (see active). Of processes, etc., "involving or produced by radioactivity," by 1903.

updated on March 31, 2021

Advertisement
Advertisement
Definitions of radioactive from WordNet

radioactive (adj.)
exhibiting or caused by radioactivity;
radioactive decay
radioactive isotope
radioactive fallout
Etymologies are not definitions. From wordnet.princeton.edu, not affiliated with etymonline.