柯林斯詞典muon /?mju??n/ 1. N a positive or negative elementary particle with a mass 207 times that of an electron and spin . It was originally called the mu meson but is now classified as a lepton μ(介)子 返回 muon劍橋詞典a type of elementary particle (= a very small piece of matter ) with the same negative charge as an electron , but much larger μ介子 比較electron neutron proton 返回 muon