calaquaintance

A long word for a long lost brother, sister, or acquaintance. Normally will be used to say that someone is unknown. C.Q. for short.

Jesse: I just found my C.Q. online.
Dave: You mean you're brother from LA
Jesse: Ya! My very own calaquaintance

Anne: Who's that person waving at you?
Frank: Don't know. Maybe he's a calaquaintance