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

Still, the current team does have a rare shot at shaping an orchestra that is not only reliably exciting and frequently profound but also casually bold and genuinely fun — making for a crucial presence in the city as well as at Geffen Hall. — Justin Davidson, Vulture, 18 Sep. 2026

North Carolina’s Senate seat is a crucial race that Democrats must flip in order to retake the Senate for the first time since 2022. — Mabinty Quarshie, The Washington Examiner, 18 Sep. 2026

Especially for the majority of streaming players now selling ads along with subscriptions, scale is crucial. — Dade Hayes, Deadline, 17 Sep. 2026

Yet, for millions living with untreatable neurological conditions, these chimeric rodents represent a crucial step forward — bringing the dark box of the human brain into the light. — Mrigakshi Dixit, Interesting Engineering, 17 Sep. 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