nuclear family

noun

Etymology: From nuclear + family.

1. The traditional western family unit, consisting of two parents (traditionally a mother and a father) and their children.

   “The initial result of that fragmentation, the nuclear family, didn’t seem so bad. But then, because the nuclear family is so brittle, the fragmentation continued. In many sectors of society, nuclear families fragmented into single-parent families, single-parent families into chaotic families or no families.”