The term FRANK HERBERT CLASSIC is a reference to the 1965 science fiction novel 'DUNE' by Frank Herbert. The crossword solution for this term is DUNE, which is a four letter word. 'DUNE' is set in the distant future and follows the story of Paul Atreides, a young nobleman who must lead his people against the forces of the evil House Harkonnen. The novel has become a classic of the science fiction genre and has spawned numerous sequels, prequels, video games, and films.