Collins COBUILD Advanced Learner's English Dictionary - must-

Must- is added to verbs such as ‘see’, ‘have’, or ‘read’ to form adjectives and nouns which describe things that you think people should see, have, or read. For example, a must-have is something which you think people should get, and a must-win game is one which a team needs to win. (JOURNALISM or INFORMAL) ...a list of must-see movies... COMB in ADJ and N-COUNT