DictionaryAI

must

MUST/mʌst/

Verbmust, musting, musted

Noun pluralmusts

7 meanings of must

Practice

  1. 1
    have toverbauxiliarymodal
    Used to say something has to be done, or is necessary.

    Think of it like a locked gate with only one key: do the thing, or stay outside.

    You must arrive on time.

    Passengers must show a valid ticket.

    UsageSay you must go (not incorrect: you must to go). You don't have to means it is not needed.

    Note
  2. 2
    surely trueverbauxiliarymodal
    Used to say something is very likely, judging from the facts.

    You must be hungry after that long hike up the mountain.

    The lights are off next door, so they must be on vacation.

    UsageSay it must be when you are sure, it can't be when you are sure it is not.

    Note
  3. 3
    essentialnounauxiliarymodalcountable
    Something you have to do or have, used as a noun.

    A good map is a must for the walk.

    Sunscreen is a must in July.

    UsageSay It's a must: you really need it.

    Similarnecessity, imperative

    Note
  4. 4
    verb
    Used to tell someone strongly that they should try something or come somewhere, because you think it is very good.

    You must try the apple pie here, because it's the best in town.

    You must come over for dinner when you're back from your trip.

    UsagePut really or simply before must for extra force: You really must try it!

    Note

Less common meanings

  1. 5
    grape juicenounauxiliarymodalcountable or uncountable
    Fresh fruit juice, usually from grapes, that is going to be, or is being, made into wine.

    Think of it like wine before it has grown up.

    The must bubbled in the vats.

    Winemakers test the sugar in the must.

    Note
  2. 6
    damp smellnounauxiliarymodalcountable or uncountable
    A stale, damp smell like an old shut room, or something that has gone stale and moldy.

    A smell of must hung in the cellar.

    The old trunk smelled of must and mothballs.

    Oppositefreshness

    Note
  3. 7
    verbauxiliaryintransitivemodal
    To go stale and smell of damp and mold, or to make something do this.

    Similarmildew

Practice

Can you tell the meanings of must apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origins

Meanings 1–4

From Old English mōste, meaning "had to," the past tense of a verb meaning to be allowed or be able to.

Checked 1 Nov 2026 · 3 facts

Meanings 5–7

From Latin mustum, coming into English through Old English and Old French.

Checked 1 Nov 2026 · 2 facts