nuclear energyBrE /ˌnjuːkliər ˈenədʒi/ 🔊NAmE /ˌnuːkliər ˈenərdʒi/ 🔊 (also ˌnuclear ˈpower) noun [uncountable] a powerful form of energy produced by converting matter into energy by splitting the nuclei (= central parts) of atoms. It is used to produce electricity. 核能；原子能