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must

v. · n.
US //ˈməst// UK //mˈʌst// must
  1. 1 obligation or rule (v.)
    A1 Beginner

    you use this to say that something is necessary or is a rule.

    indicates a requirement, imperative, or strong obligation imposed by the speaker or an external authority.

    Example

    You must wear a seatbelt at all times while the car is moving.

    Example

    All employees must complete the safety training module before they are permitted to operate the heavy machinery on the factory floor.

    Usage

    followed by the bare infinitive without 'to'
    • mustn't
    Pitfall
    I must to go now.
    I must go now.

    Do not use 'to' after must. It is followed by the base form of the verb without 'to'.

  2. 2 logical certainty (v.)
    A2 Elementary

    you use this when you are almost certain that something is true based on the evidence.

    expresses a logical deduction or the speaker's certainty that a particular state of affairs exists.

    Example

    You have been working all day, so you must be very tired.

    Example

    Given the fingerprints found at the scene, the investigators concluded that the suspect must have entered through the unlocked side window.

    Usage

    often used with 'be' or 'have been'
    • can't
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  1. 3 a requirement (n.)
    B1 Intermediate

    something that is necessary to have or do.

    something that is mandatory, essential, or highly recommended.

    Example

    If you visit Paris, seeing the Eiffel Tower is a must.

    Example

    For any serious scholar of ancient history, visiting the national archives is an absolute must during their research trip.

    Usage

    often used in the phrase 'a must' or 'a must-have'
  2. 4 grape juice (n.)
    C2 Proficiency Technical Cooking

    the juice from crushed grapes before it becomes wine.

    the unfermented or fermenting juice expressed from fruit, especially grapes.

    Example

    The workers collected the fresh must in large wooden vats to begin the fermentation.

    Example

    The quality of the wine depends heavily on the sugar content and acidity of the must before the yeast is introduced.

    Usage

    uncountable in this sense

Etymology 1

From Middle English moste ("must", literally, "had to", the past tense of Middle English moten (“to have to”)), from Old English mōste (“had to”), 1st & 3rd person singular past tense of mōtan (“to be allowed, be able to, have the opportunity to, be compelled to, must, may”), from Proto-Germanic *mōtaną. Cognate with Dutch moest (“had to”), German musste (“had to”), Swedish måste (“must, have to, be obliged to”). More at mote.

Etymology 2

From Middle English must, from Old English must and Old French must, most, both from Latin mustum.

Etymology 3

See musth.

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