Noun
friend of a friend (plural friends of friends)
An acquaintance known vaguely through a mutual friend; someone that one does not know well.
I wrote a query letter to an editor - a friend of a friend. The editor called me an idiot, told me never to contact an editor directly, and then recommended three literary agents he had worked with before. Laurie Fox was one of them, and I've never looked back. Daniel H. Wilson