cousin

A cousin is a relative who shares at least one common ancestor with another person. The most common usage refers to a first cousin, the child of one’s aunt or uncle. A second cousin is the child of one’s parent's cousin, and more distant cousins exist as well. The terms used to describe these relationships include “first,” “second,” and so on, while the concept of being “removed” indicates a difference in generations; for example, a first cousin once removed is either the child of your first cousin or your parent’s first cousin.

The English word cousin comes from Old French cosin or cousin, derived from Latin consobrinus, meaning roughly “related by blood.” The term has long been used in many languages with similar meanings to denote kinship through blood ties rather than by marriage.

In practice, cousins can have close or distant ties depending on family structure, culture, and geography. In some cultures, cousins form central social networks and may participate in shared rituals and responsibilities. Some regions practice cousin marriage, which is legal in some jurisdictions and restricted or prohibited in others due to genetic considerations and social norms. The term cousin is also used more broadly in informal speech to refer to acquaintances treated as family.

In kinship and genealogy, cousins are a basic category of blood relations, described in terms of degree (first, second, etc.) and generation (removed). The study of cousin relationships falls under the broader field of consanguinity and kinship terminology.