In kinship terminology, a cousin's a relative with whom one shares a common ancestor. In modern usage, the term's rarely used when referring to a relative in one's own line of descent, or where there's a more specific term to describe the relationship: for example, brother, sister, aunt, uncle. The term blood relative can be used synonymously, and underlines the existence of a genetic link. A system of degrees and removes's used to describe the relationship between the two cousins and the ance… (More on Cousin)