nuclear family
noun [ C ] social science specialized uk/ˌnjuː.klɪə ˈfæm.əl.i/ us/ˌnuː.kliː.ɚ ˈfæm.əl.i/
（由父母与子女组成的）核心家庭
a family consisting of two parents and their children, but not including aunts, uncles, grandparents, etc.
Compare: extended family