crucial

American  

[kroo-shuhl] / ˈkru ʃəl /

adjective

1. involving an extremely important decision or result; decisive; critical.

   a crucial experiment.

   Synonyms:

   significant, essential, vital, momentous

2. severe; trying.

3. of the form of a cross; cross-shaped.

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crucial British  

/ ˈkruːʃəl /

adjective

1. involving a final or supremely important decision or event; decisive; critical

2. informal very important

3. slang very good

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Usage

What does crucial mean? Crucial means extremely important or involving an extremely important decision or course of action. Close synonyms are critical and decisive. The word crucial is usually used to describe pivotal moments, choices, or actions that will affect everything that follows, as in We’re at a crucial point in the process—we need to make some big decisions. Sometimes, crucial is simply used to describe something that’s extremely important, as in Getting enough sleep is crucial for staying healthy.  Example: I can’t express how absolutely crucial it is to surround yourself with the right friends.

Other Word Forms

• cruciality noun
• crucially adverb
• noncrucial adjective
• noncrucially adverb
• precrucial adjective

Etymology

Origin of crucial

First recorded in 1700–10; from Latin cruci- (stem of crux cross ( def. ) ) + -al ¹ ( def. )

Explanation

The word crucial describes something that is important or essential to success, like the crucial dress rehearsals that ensure everything will run smoothly on your play's opening night. Usage experts insist that the word crucial should be used only to describe something that is truly critical for solving a problem or for resolving a situation, such as a crucial vote that determines a final outcome. In this case the crucial vote is decisive: it determines the outcome. But the word has gained popularity as a way to say that something is important. You might hear someone say, for example, that it is crucial to allow employees to vote on the new schedule to make them feel like they’re part of the process. In this case the sense is “important”: nothing decisive is taking place.

Example Sentences

The foundations were laid during pre-season, with Lampard's calming influence crucial in his first summer with the group, having replaced fan favourite Mark Robins in November 2024.

From BBC • Apr. 17, 2026

The change of control took longer than expected, Clear Street analyst Tim Moore said, but it remains a crucial step toward getting final approval from the Greenland government to start drilling.

From Barron's • Apr. 17, 2026

The crucial issue for UnitedHealth is that Optum’s business model relies on serving chronic patients.

From The Wall Street Journal • Apr. 17, 2026

Estate planning is crucial, especially for someone who is single and has no heirs.

From MarketWatch • Apr. 17, 2026

It would be wrong, however, to concentrate solely on the word ‘evidence’ rather than the concept which it expresses, for if we do so we will miss a crucial development.

From "The Invention of Science" by David Wootton

Related Words

• central
• compelling
• deciding
• decisive
• essential
• imperative
• momentous
• necessary
• pivotal
• pressing
• touchy
• urgent
• vital