A concept expressing how cousins of different generations are related. If Suzanne and Leah are first cousins, and Leah has a child Bob, then Bob is Suzanne's first cousin once removed, because he's one generation below her in the family tree. If Bob becomes father to John, then John and Suzanne are first cousins twice removed, because they are two generations apart.

Contrast with the relationship of Suzanne's child Mary to Bob; Mary and Bob are second cousins, because they are one generation farther down from their common ancestor than Suzanne and Leah are.