radioactivityEnglish → ChineseOxford English–Chineseradioactivity /BrE ˌreɪdɪəʊakˈtɪvɪti , AmE ˌreɪdioʊækˈtɪvədi / noun [uncountable] 1 (emission of radiation) 放射性 2 (radiation) 放射线