must

¹

[muhst]

auxiliary verb

1. to be obliged or bound to by an imperative requirement.

   I must keep my word.

2. to be under the necessity to; need to.

   Animals must eat to live.

3. to be required or compelled to, as by the use or threat of force.

   You must obey the law.

4. to be compelled to in order to fulfill some need or achieve an aim.

   We must hurry if we're to arrive on time.

5. to be forced to, as by convention or the requirements of honesty.

   I must say, that is a lovely hat.

6. to be or feel urged to; ought to.

   I must buy that book.

7. to be reasonably expected to; is bound to.

   It must have stopped raining by now. She must be at least 60.

8. to be inevitably certain to; be compelled by nature.

   Everyone must die.

verb (used without object)

1. to be obliged; be compelled.

   Do I have to go? I must, I suppose.

2. Archaic.,  (sometimes used with ellipsis of go, get, or some similar verb readily understood from the context).

   We must away.

adjective

1. necessary; vital.

   A raincoat is must clothing in this area.

noun

1. something necessary, vital, or required.

   This law is a must.

must

²

[muhst]

noun

1. new wine; the unfermented juice as pressed from the grape or other fruit.

must

³

[muhst]

noun

1. mold; moldiness; mustiness.

   a castle harboring the must of centuries.

must

⁴

[muhst]

noun

1. musk, especially a powder made from musk.

verb (used with object)

1. to powder (the hair).

must

¹

/ məst, mʌst, məs /

verb

1. used as an auxiliary to express obligation or compulsion: you must pay your dues . In this sense, must does not form a negative. If used with a negative infinitive it indicates obligatory prohibition

2. used as an auxiliary to indicate necessity

   I must go to the bank tomorrow

3. used as an auxiliary to indicate the probable correctness of a statement

   he must be there by now

4. used as an auxiliary to indicate inevitability

   all good things must come to an end

5. 1. on the part of the speaker when used with I or we

      I must finish this

   2. on the part of another or others as imputed to them by the speaker, when used with you, he, she, they, etc

      let him get drunk if he must

6. (used emphatically) used as an auxiliary to express conviction or certainty on the part of the speaker

   he must have reached the town by now, surely

   you must be joking

7. (foll by away) used with an implied verb of motion to express compelling haste

   I must away

noun

1. an essential or necessary thing

   strong shoes are a must for hill walking

must

²

/ mʌst /

noun

1. mustiness or mould

must

³

/ mʌst /

noun

1. the newly pressed juice of grapes or other fruit ready for fermentation

must

⁴

/ mʌst /

noun

1. a variant spelling of musth

must-

⁵

combining form

1. indicating that something is highly recommended or desirable

   a must-see film

   this season's must-haves

Word History and Origins

Origin of must¹

First recorded before 900; Middle English most(e), Old English mōste (past tense); cognate with German musste. See mote ²

Origin of must²

First recorded before 900; Middle English, Old English, from Latin mustum, short for vīnum mustum “new wine”

Origin of must³

First recorded in 1595–1605; back formation from musty ¹

Origin of must⁴

First recorded in 1480–90; earlier moist, from Middle French must, variant of musc; musk

Word History and Origins

Origin of must¹

Old English mōste past tense of mōtan to be allowed, be obliged to; related to Old Saxon mōtan, Old High German muozan, German müssen

Origin of must²

C17: back formation from _musty

Origin of must³

Old English, from Latin mustum new wine, must, from mustus (adj) newborn

Idioms and Phrases

see a must; show must go on.

Synonym Study

Must, ought, should express necessity or duty. Must expresses necessity or compulsion: I must attend to those patients first. Soldiers must obey orders. Ought (weaker than must ) expresses obligation, duty, desirability: You ought to tell your mother. Should expresses obligation, expectation, or probability: You are not behaving as you should. Children should be taught to speak the truth. They should arrive at one o'clock.

Example Sentences

Menacing intonations about an invasion that must be stopped at all costs.

From Los Angeles Times

The board determined that immigration judges had no authority to issue bonds because immigrants “who are present in the United States without admission ... must be detained for the duration of their removal proceedings.”

From Los Angeles Times

On commentary for Sky Sports on the night of 6 September 1995 was Martin Tyler, who initially thought the referee's whistle must have gone - after all, the linesman put his flag up - but play continued.

From BBC

California residents must sign an affidavit under penalty of perjury to register to vote.

From Los Angeles Times

The new Max app is being aggressively promoted by pop stars and bloggers, and since 1 September all devices sold in Russia must have Max pre-installed.

From BBC

Related Words

• precondition 
• prerequisite 
• requisite