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

Lucy Bronze Will be 35 years old next summer but her performance against Spain last week shows that those trademark driving runs remain crucial. —Megan Feringa, New York Times, 20 Apr. 2026

Socialists like to spend money — lots of other people’s money, of course — and Mamdani has been hampered by the fiscal stewards of Albany who, thankfully for New York City, aren’t likely to allow his more egregious schemes that would only drive away more of the city’s crucial affluent class. —The Editorial Board, Chicago Tribune, 19 Apr. 2026

Of particular concern is the Strait of Hormuz, the crucial waterway off Iran, where more than 20% of the world's oil supply normally passes. —Steve Kopack, NBC news, 19 Apr. 2026

Being a gracious loser is crucial to maintaining democracy and self-governance. —New York Daily News, Twin Cities, 19 Apr. 2026

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