The term 'Hitchcock Nail-Biter' is a phrase used to describe the suspenseful films of Alfred Hitchcock, the famous British director. The crossword solution for this term is 'ROPE', which is a reference to one of Hitchcock's most iconic films, ROPE (1948). The film follows two men who commit a murder and attempt to cover it up by hiding the body in a chest. The tension builds as the men try to keep their crime a secret, creating a nail-biting experience for viewers.