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

Kean is still running for a third term in the 7th Congressional District, a purple swing seat that will be crucial to the GOP’s effort to hold its House majority in November. —Hailey Bullis, The Washington Examiner, 31 May 2026

For Restrepo, having a top-down approach to goalkeeping and set pieces is crucial for City to build upon the successes of this season, particularly with the introduction of full-time academies in England. —Megan Feringa, New York Times, 31 May 2026

Democrats consider the Maine race crucial to regain the Senate. —Mariana Alfaro, Washington Post, 31 May 2026

Soaring jet fuel costs and disrupted air routes related to the Iran war are driving up airfares and threatening Southeast Asia’s crucial summer tourist season, in a region that has yet to recover from COVID-19 disruptions. —Anton L. Delgado, Los Angeles Times, 31 May 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