Dictionary > English Dictionary > Definition, synonym and antonym of must
Meaning of must by Wiktionary Dictionary



    • ( stressed ) IPA: /mʌst/, X-SAMPA: /mVst/
    • ( unstressed ) IPA: /məs( t )/, X-SAMPA: /m@s( t )/
    • Rhymes: -ʌst
    • Homophone: mussed

    Etymology 1

    From Middle English moste ( “must”, literally “had 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” ). Cognate with Dutch moest ( “had to” ), German musste ( “had to” ), Swedish måste ( “must, have to, be obliged to” ). More at mote .



    1. ( modal auxiliary, defective ) to do with certainty; indicates that the speaker is certain that the subject will have executed the predicate
      If it rained all day, it must be very wet outside .
      You picked one of two, and it wasn't the first: it must have been the second .
    2. ( modal auxiliary, defective ) to do as a requirement; indicates that the sentence subject is required as an imperative or directive to execute the sentence predicate, with failure to do so resulting in a negative consequence
      You must arrive in class on time. — the requirement is an imperative
      This door handle must be rotated fully. — the requirement is a directive

    Usage notes
    You must not read that book. ( It is necessary that you not read that book. )
    You need not read that book. ( It is not necessary that you read that book. )
    See also
    • Appendix:English tag questions


    must ( plural: musts )

    1. Something that is mandatory or required
      If you'll be out all day, sunscreen is a must .

    Etymology 2

    Old French must, most, from Latin mustum


    must ( plural: musts )

    1. Something that exhibits the property of being stale or musty
    2. Fruit juice that will ferment or has fermented, usually grapes
    • Must on Wikipedia .

    Etymology 3

    Persian مست ( mast, “drunk, inebriated” ) .



    1. A time during which male elephants exhibit increased levels of sexual activity and aggressiveness ( also musth )



    • smut, stum, tums, UMTS, UTMS

Explanation of must by Wordnet Dictionary


    1. highly recommended

    2. a book that is must reading
    1. the quality of smelling or tasting old or stale or mouldy

    2. grape juice before or during fermentation

    3. a necessary or essential thing

    4. seat belts are an absolute must