non-identical twin
noun🔊/ˌnɒn aɪˌdentɪkl ˈtwɪn/
🔊/ˌnɑːn aɪˌdentɪkl ˈtwɪn/
(also fraternal twin, specialist dizygotic twin)
either of two children or animals born from the same mother at the same time but not from the same egg 二卵双生；异卵双生