A more thorough explanation:

Definition: Kin refers to a family member who is related to you by blood. This term is usually used to describe relationships that are based on blood ties or consanguinity. However, it can also be used to refer to relatives who are related to you through marriage or adoption. Other terms that are used to describe kin include kindred, kinsman, and kinswoman.

Examples:

• Your parents, siblings, grandparents, aunts, uncles, and cousins are all considered your kin.
• If your aunt marries someone, their children become your kin through marriage.
• If you are adopted, your adoptive parents and siblings become your kin.

The examples illustrate the definition of kin by showing that it refers to family members who are related to you by blood, marriage, or adoption. Your kin includes your immediate family members, as well as more distant relatives such as aunts, uncles, and cousins. Even if you are not related to someone by blood, they can still become your kin through marriage or adoption.