The crossword solution for the term 'Cyclo-ending' is 'Tron', which is a four letter word. Tron is a 1982 science fiction film directed by Steven Lisberger and produced by Walt Disney Pictures. The film follows a computer programmer who is transported inside the software world of a mainframe computer where he interacts with programs in his attempt to escape. The film was a box office success and has since become a cult classic.