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

Goaltender Sergei Bobrovsky and backup Daniil Tarasov will both be free agents in a matter of days, leaving Florida with a crucial hole — or net – to fill. — Ava Dicecca, Sun Sentinel, 30 June 2026

Besides the costume racks, another crucial backstage element are the vocal booths, where the ensemble contributes to the musical soundscape from behind the curtain. — Los Angeles Times, 30 June 2026

Barger, sidelined since mid-May with elbow inflammation, is crucial for roster flexibility. — Peter Chawaga, Forbes.com, 29 June 2026

Relief organizations say the first 72 hours after a natural disaster is the most crucial time period for rescues, though survival can be extended if people have access to food and water. — Juan Pablo Arraez, Chicago Tribune, 29 June 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