ra‧di‧o‧ac‧tive /ˌreɪdiəʊˈæktɪv◂ $ -dioʊ-/
adjective a radioactive substance is dangerous because it contains
radiation (=a form of energy that can harm living things):
the problem of how to dispose of radioactive waste a consignment of highly radioactive plutonium [TahlilGaran] Dictionary of Contemporary English ▲