subatomic particle
noun [ C ] physics specialized uk/sʌb.əˌtɒm.ɪk ˈpɑː.tɪ.kəl/ us/sʌb.əˌtɑː.mɪk ˈpɑːr.t̬ə.kəl/
亚原子粒子
an extremely small piece of matter that is smaller than an atom or found inside an atom, such as a proton, neutron, or electron