must

1 strong /mVst/ modal verb (negative short form mustn't)

1 (past usually had to) to have to do something because the situation forces you, because of a rule or law, or because you feel that you should: All passengers must wear seat belts. | You mustn't tell anyone about this - it's a secret. | I don't really want to make the appointment, but I suppose I must. | Under no circumstances must any member of staff socialize with the patients. | Apologize? Must I? It was all her own fault. | I must admit/say etc: I must admit, I was surprised when he passed his driving test first time.

—compare have 3

2 (past usually must have) used when you are guessing that something is true or that something has happened because there seems to be no other possibility: Sam must be nearly 90 years old now. | Buying roses? It must be love. | He must have been drunk to say that. | There must have been ten of them, all hiding in my attic.

3

a) used to suggest that someone does something, especially because you think they will enjoy it very much or you think it is a very good idea: You must go and see the new Spielberg movie, the special effects are amazing.

b) used when you want to do something and hope to do it soon: We must come over and try out that new barbecue of yours.

4 if you must used to tell someone that they are allowed to do something but that you do not approve or agree with it: "Can I borrow your car, Mum?" "If you must." | if you must do sth: If you must smoke, do it outside please.

5 you must be joking used when you think someone's suggestion is silly or stupid: -2000 for that old car? You must be joking!

2 noun

1 a must something that you must do or must have: Warm clothes are a must in the mountains.

2 (U) the liquid from which wine is made; grape juice