What is "red diaper baby"

alt. (context chiefly US English) A child of parents who belonged to a communist party (usually the (w: United States Communist Party)), identified as communists, or were supportive of communist ideas and goals. n. (context chiefly US English) A child of parents who belonged to a communist party (usually the (w: United States Communist Party)), identified as communists, or were supportive of communist ideas and goals.

A red diaper baby is a child of parents who were members of the United States Communist Party (CPUSA) or were close to the party or sympathetic to its aims.