The slang term "rellie" is often used as a shortened version of the word "relative." Synonyms for "rellie" include kin, kinsfolk, kindred, family members, blood relations, and folks. These words all refer to a person's family members or relations. Other synonyms for "rellie" could include clan, tribe, or lineage. These words all connote a group of people with a shared ancestry or heritage. Depending on the context, "rellie" can be seen as a casual or informal way to refer to family members. However, it's important to keep in mind that different people may use different terms to describe their own family members.