Must

Pronunciation

• stressed IPA: /mÊŒst/
• unstressed IPA: /mÉ™s(t)/
• Rhymes: -ÊŒst
• Homophones: mussed

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.

Verb

verb

1. (modal auxiliary, defective) to do with certainty; indicates that the speaker is certain that the subject will have executed the predicateIf it has 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.Arise, and go into the city, and it shall be told thee what thou must do. (Bible, Acts 9:6)
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 consequenceYou must arrive in class on time. — the requirement is an imperativeThis door handle must be rotated fully. — the requirement is a directiveThe children must be asleep by now.

Usage notes

(auxiliary, to do with certainty) Compare with weaker auxiliary verb should, indicating a strong probability of the predicate's execution.

(auxiliary, to do as a requirement) Compare with weaker auxiliary verb should, indicating mere intent for the predicate's execution; and stronger auxiliary verb will, indicating that the negative consequence will be unusually severe.

The past tense of "must" is also "must"; however, this usage is almost always literary (see Fritz Leiber quotation above). The past sense is usually conveyed by had to. It is possible to use be bound to for the past also. For this reason, have to and be bound to are also used as alternatives to must in the present and future.

The principal verb, if easily supplied, may be omitted. In modern usage this is mainly literary (see Housman and Tolkien quotations above).

Must is unusual in its negation. Must not still expresses a definite certainty or requirement, with the predicate negated. Need, on the other hand, is negated in the usual manner. Compare:

The second person singular no longer adds "-est" (as it did in Old English).

Full definition of must

Noun

1. Something that is mandatory or requiredIf you'll be out all day, a map is a must.

Synonyms

• imperative

Antonyms

• no-no

Old French must, most, from Latin mustum

Noun

1. The property of being stale or musty
2. Something that exhibits the property of being stale or musty
3. Fruit juice that will ferment or has fermented, usually grapes
• LongfellowNo fermenting must fills ... the deep vats.

Verb

1. (transitive) To make musty.
2. (intransitive) To become musty.

Persian مست (mast, "drunk, inebriated"), from Middle Persian 𐭬𐭮𐭲.

Noun