/ˌreɪdiəʊˈæktɪv ||; ˌredɪoˈæktɪv/adj sending out powerful and very dangerous rays that are produced when atoms are broken up. These rays cannot be seen or felt but can cause serious illness or death. 放射性的: the problem of the disposal of radioactive waste from power stations 发电站放射性废料的处理问题 ☞Look at radiation. 参看radiation。 ➔radioactivity /ˌreɪdiəʊækˈtɪvəti ||; ˈredɪˌoækˈtɪvətɪ/ noun [U]