mesonPronunciation: /ˈmiːzɒn, ˈmɛzɒn/Definition of meson noun Physics a subatomic particle which is intermediate in mass between an electron and a proton and transmits the strong interaction that binds nucleons together in the atomic nucleus. Derivatives mesonicPronunciation: /mɪˈzɒnɪk/ adjective Origin: 1930s: from meso- 'intermediate' + -onmeson in other Oxford dictionaries Definition of meson in the US English dictionary