Cousin

The word cousin refers to a relationship between people who share a certain degree of common ancestry. The word has also been used to refer to common membership in a specific class of people, but that usage is much less common.

Two people who are cousins have a common ancestor without one being a direct ancestor of the other, are not siblings (ie, the common ancestor is not a parent), and are not related as aunt/uncle and niece/nephew. Most commonly, people considered cousins are in the same generation from the common ancestor, though in Anglo-American legal use, this is not required.

In informal usage, within an extended family, cousins are those non-sibling relatives who are of approximately similar age, while aunts and uncles are the female and male non-ancestral relatives who are of approximately the age of the parents of the person.

The relationship most commonly referred to as "cousin" is that of first cousin, where the two people share grandparents. Second cousins are people who share great-grandparents, but no closer relations. As the degree of closest common ancestry increases, the degree of cousinship increases as well.