must

[ muhst ]

/ mʌst /

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See synonyms for: must / muster on Thesaurus.com

auxiliary verb

to be obliged or bound to by an imperative requirement: I must keep my word.

to be under the necessity to; need to: Animals must eat to live.

to be required or compelled to, as by the use or threat of force: You must obey the law.

to be compelled to in order to fulfill some need or achieve an aim: We must hurry if we're to arrive on time.

to be forced to, as by convention or the requirements of honesty: I must say, that is a lovely hat.

to be or feel urged to; ought to: I must buy that book.

to be reasonably expected to; is bound to: It must have stopped raining by now. She must be at least 60.

to be inevitably certain to; be compelled by nature: Everyone must die.

verb (used without object)

to be obliged; be compelled: Do I have to go? I must, I suppose.

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

adjective

necessary; vital: A raincoat is must clothing in this area.

noun

something necessary, vital, or required: This law is a must.

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Origin of must

First recorded before 900; Middle English most(e), Old English mōste (past tense); cognate with German musste. See mote²

synonym study for must

1. 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.

Other definitions for must (2 of 4)

must²

[ muhst ]

/ mʌst /

noun

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

Origin of must

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

Other definitions for must (3 of 4)

must³

[ muhst ]

/ mʌst /

noun

mold; moldiness; mustiness: a castle harboring the must of centuries.

Origin of must

First recorded in 1595–1605; back formation from musty¹

Other definitions for must (4 of 4)

must⁴

[ muhst ]

/ mʌst /

Obsolete

noun

musk, especially a powder made from musk.

verb (used with object)

to powder (the hair).

Origin of must

⁴

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use must in a sentence

Ohio is a must-win swing state for Republicans if they are to reclaim the White House.
John Kasich: The GOP’s Hobbled 2016 Dark Horse|W. James Antle III|November 3, 2014|DAILY BEAST
During the Showtime era, Lakers games became a must-see event that attracted fans and celebrities alike.
How to Rescue the Clippers From Donald Sterling’s Racist Clutches|Jesse Lawrence|April 29, 2014|DAILY BEAST
In other words, this book is a must-read for every U.S. citizen.
Beauty and Subversion in the Secret Poems of Afghan Women|Daniel Bosch|April 6, 2014|DAILY BEAST
Meyers still has a way to go if he wants to make his new weeknight gig must-see daily viewing.
Seth Meyers Gets Off to a Rocky Start on 'Late Night'|Kevin Fallon|February 25, 2014|DAILY BEAST

It's now a must-have wardrobe staple, similar to that of the t-shirt or a pair of jeans.
Diane von Furstenberg Celebrates 40 Years of the Wrap Dress|Erin Cunningham|January 14, 2014|DAILY BEAST
All of a sudden the Writer and the Sketcher found themselves thrust into the presence of He-who-must-be-obeyed.
Punch's Almanack for 1890|Various
All of a sudden, with one accord, they put to the Sphinx the question that He-who-must-be-obeyed had asked them.
Punch's Almanack for 1890|Various
Had not He-who-must-be-obeyed ordered them to seek out the solution of the Great Conundrum?
Punch's Almanack for 1890|Various
The starching, the fluting, the ironing, all take precious hours that might be employed upon some of the must-haves.
The Secret of a Happy Home (1896)|Marion Harland
It was that terrible once-on-board-the-lugger-and-the-girl-is-mine-I-must-and-shall-possess-her feeling in its most acute form.
The Limit|Ada Leverson

British Dictionary definitions for must (1 of 5)

must¹

/ (mʌst, unstressed məst, məs) /

verb (takes an infinitive without to or an implied infinitive)

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

used as an auxiliary to indicate necessityI must go to the bank tomorrow

used as an auxiliary to indicate the probable correctness of a statementhe must be there by now

used as an auxiliary to indicate inevitabilityall good things must come to an end

(used as an auxiliary to express resolution)

on the part of the speaker when used with I or weI must finish this
on the part of another or others as imputed to them by the speaker, when used with you, he, she, they, etclet him get drunk if he must

(used emphatically) used as an auxiliary to express conviction or certainty on the part of the speakerhe must have reached the town by now, surely; you must be joking

(foll by away) used with an implied verb of motion to express compelling hasteI must away

noun

an essential or necessary thingstrong shoes are a must for hill walking

Word Origin for must

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

British Dictionary definitions for must (2 of 5)

must²

/ (mʌst) /

noun

mustiness or mould

Word Origin for must

C17: back formation from musty

British Dictionary definitions for must (3 of 5)

must³

/ (mʌst) /

noun

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

Word Origin for must

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

British Dictionary definitions for must (4 of 5)

must⁴

/ (mʌst) /

noun

a variant spelling of musth

British Dictionary definitions for must (5 of 5)

must-

combining form

indicating that something is highly recommended or desirablea must-see film; this season's must-haves

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with must

must

see a must; show must go on.

must

Origin of must

synonym study for must

Other definitions for must (2 of 4)

Origin of must

Other definitions for must (3 of 4)

Origin of must

Other definitions for must (4 of 4)

Origin of must

Words related to must

How to use must in a sentence

British Dictionary definitions for must (1 of 5)

Word Origin for must

British Dictionary definitions for must (2 of 5)

Word Origin for must

British Dictionary definitions for must (3 of 5)

Word Origin for must

British Dictionary definitions for must (4 of 5)

British Dictionary definitions for must (5 of 5)

Other Idioms and Phrases with must