consanguineous

con·san·guin·e·ous

adj \ˌkän-ˌsan-ˈgwin-ē-əs, -ˌsaŋ-\

Definition of CONSANGUINEOUS

: of the same blood or origin; specifically : relating to or involving persons (as first cousins) that are relatively closely related <consanguineous marriages>

—con·san·guin·i·ty \-ˈgwin-ət-ē\ noun, plural con·san·guin·i·ties