crucial
Americanadjective
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involving an extremely important decision or result; decisive; critical.
a crucial experiment.
- Synonyms:
- significant, essential, vital, momentous
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severe; trying.
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of the form of a cross; cross-shaped.
adjective
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involving a final or supremely important decision or event; decisive; critical
-
informal very important
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slang very good
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
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.
Vocabulary lists containing crucial
List 1
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Jim Burke's Academic Vocabulary List
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Walk Two Moons
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
That sales-tax treatment is a crucial piece of financing because the computer chips and servers inside the facilities represent a significant chunk of the projects’ costs, and because that equipment gets replaced every few years.
From The Wall Street Journal ● Sep. 9, 2026
Treasury Department and Japan’s Ministry of Finance engineered a rebound from the crucial 164 level.
From MarketWatch ● Sep. 8, 2026
Being able to use her foot normally could play a crucial role in her ability to carry and care for her offspring.
From Science Daily ● Sep. 8, 2026
At a time when many big-name comedians continue to fall out of favor with viewers, that might be Hargitay’s most crucial asset.
From Salon ● Sep. 8, 2026
He felt that he couldn’t lie if asked a direct question, and yet if he simply refused to answer, the assumption was that he was hiding something crucial.
From "Endgame" by Frank Brady
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
