柯林斯詞典radium /?re?d??m/ 1. N-UNCOUNT Radium is a radioactive element which is used in the treatment of cancer. 鐳 返回 radium劍橋詞典a radioactive chemical element that is used in the treatment of some diseases , especially cancer （尤指用于治療癌癥的）鐳 返回 radium