/ˌreɪdiˈeɪʃn ||; ˌredɪˈeʃən/noun[U] 1 powerful and very dangerous rays that are sent out from certain substances. You cannot see or feel radiation but it can cause serious illness or death 辐射 ☞Look at radioactive. 参看radioactive。
2 heat, light or energy that is sent out from sth 放热；发光；辐射能: ultraviolet radiation 紫外线辐射