A cousin is a relative that is the child of a parent's sibling; this is more specifically referred to as a first cousin. . More generally, in the kinship system used in the English-speaking world, a cousin is a type of relationship in which relatives are two or more generations away from their most recent common ancestor. For this definition degrees and removals are used to further specify the relationship. Degree measures how distant the relationship is from the most recent common ancestor(s).
https://en.wikipedia.org/wiki/Cousin