radioactivity
radioactivity /ˌreɪ.di.əʊ.ækˈtɪv.ɪ.ti/ aep /-oʊ.ækˈtɪv.ə.t̬i/ noun [U]
1 F0 the quality that some atoms have of producing energy, which can be very harmful to health Thesaurus+: ↑Radiation and radioactivity2 F0 the energy produced by atoms in this way: » A dangerous amount of radioactivity was released into the environment last month.Thesaurus+: ↑Radiation and radioactivity |