Owl And Dog Friends

• Best friend (or the closest friend): A person with whom someone shares extremely strong interpersonal ties with as a friend.
• BFF ("best friend forever"): Slang used primarily in the USA by teenage and young adult women to describe a girl friend or close best friend.
• Blood brother or blood sister: Either people related by birth, or a circle of friends who swear loyalty by mingling the blood of each member together though not recommended for risk of blood disease.
• Boston marriage: An antiquated American term used during the 19th and 20th centuries to denote two women who lived together in the same household independent of male support. Relationships were not necessarily sexual. It was used to quell fears of lesbians after World War I.