must is one of the 1000 most common headwords.
music - must - n

Pronunciation

change

Present
must

Past
none

Negative
mustn't

  1. (modal) Must is usually used to tell someone they have no choice about doing something because it is important or because of a rule or law.
    She must get her medicine soon or she will die.
  2. (modal) If you say something must be true, you say you have come to believe that it is true.
    I must have left my phone at the restaurant.
    She must not have the note if you've got it.