Blood relationship is a term used to describe the connection between two people who are related by blood. CONSANGUINITY (13 letters) is a term used to describe the relationship between two people who share a common ancestor, such as siblings, parents, and grandparents. KINSHIP (7 letters) is a term used to describe the relationship between two people who are related by marriage or adoption, such as in-laws, step-parents, and step-siblings. KINDRED (7 letters) is a term used to describe the relationship between two people who are related by blood, marriage, or adoption. All three terms are used to describe the various types of relationships that exist between family members.