adjective/ʁa.djɔ.ak.tif/
radioactive
“1898, Pierre Curie and Marie Curie, title of article in Comptes rendus de l'Académie des Sciences t. 127” — On a new radioactive substance contained in pitchblende
Related: déchet radioactif, radioactivité
Coined by Pierre Curie and Marie Curie in 1898 from radio- + actif.