radioactivity
ra.dio.ac.tiv.i.ty \-.ak-'tiv-*t-e-\ n [ISV] : the property possessed by some elements (as uranium) of spontaneously em itting alpha or beta rays and sometimes also gamma rays by the disintegration of the nuclei of atoms
ra.dio.ac.tiv.i.ty \-.ak-'tiv-*t-e-\ n [ISV] : the property possessed by some elements (as uranium) of spontaneously em itting alpha or beta rays and sometimes also gamma rays by the disintegration of the nuclei of atoms