crucial

adjective

cru·​cial ˈkrü-shəl 

1

a

: important, significant

… what use we make of them will be the crucial question.

—Stanley Kubrick

Vitamins are crucial for maintaining good health.

b

: important or essential as resolving a crisis : decisive

She played a crucial role in the negotiations.

c

: marked by final determination of a doubtful issue

the crucial game of a series

2

archaic : cruciform

Synonyms of crucial

• key
• critical
• vital

Choose the Right Synonym for crucial

acute, critical, crucial mean of uncertain outcome.

acute stresses intensification of conditions leading to a culmination or breaking point.

an acute housing shortage

critical adds to acute implications of imminent change, of attendant suspense, and of decisiveness in the outcome.

the war has entered a critical phase

crucial suggests a dividing of the ways and often a test or trial involving the determination of a future course or direction.

a crucial vote

Examples of crucial in a Sentence

Vitamins are crucial for maintaining good health.

It's crucial that we arrive before 8 o'clock.

Teachers are crucial to the success of the school.

She played a crucial role in the meeting.

Recent Examples on the Web

Another crucial shift in people’s conception of literature came from twentieth-century Africa, Asia, and South America, where post-colonial thinkers conceptualized literature very differently—and more politically—than the individualistic European and American mind-set did. —Vauhini Vara, New Yorker, 20 Dec. 2025

The alternative budget proposal championed by a group of Chicago aldermen won a crucial first full City Council vote on Friday, even as Mayor Brandon Johnson made a last-ditch effort to reintroduce the controversial corporate head tax in his 2026 plan. —Megan De Mar, CBS News, 19 Dec. 2025

Broccoli contains powerful plant compounds that may support hormone balance, particularly estrogen, a hormone crucial for metabolism and reproductive function. —Caitlin Pagán, Verywell Health, 19 Dec. 2025

In the Western mountains where snow is crucial for ski tourism — not to mention water for millions of acres (hectares) of crops and the daily needs of tens of millions of people — much less snow than usual has piled up. —Mead Gruver, Fortune, 19 Dec. 2025

Word History

Etymology

French, from Latin cruc-, crux cross

First Known Use

1706, in the meaning defined at sense 2

Rhymes for crucial

• trucial

Kids Definition

crucial

adjective

cru·​cial ˈkrü-shəl 

1

: being a final or very important test or decision : decisive

the crucial game of a series

2

: very important : significant

water is a crucial element in our weather

crucially

ˈkrüsh-(ə-)lē

adverb

Etymology

from French crucial "having the form of a cross, being or involving a crisis," from Latin cruc-, crux "cross, trouble, torture" — related to cross, crucify, crux