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.
They ask what are the priorities, what are the things we do that are crucial and which are less important?
From BBC ● Oct. 5, 2026
They are crucial for directing the body's immune defences and are targets for research into treatments of several inflammatory and autoimmune diseases.
From Barron's ● Oct. 5, 2026
"Justice delayed is justice denied, and I am committed to maximising efficiencies in our system alongside record investment. I remain committed to structural reform which is crucial if we are to bring down the backlog."
From BBC ● Oct. 4, 2026
It was the most crucial snap of the season, and time for Michigan’s $3 million investment to deliver.
From The Wall Street Journal ● Oct. 4, 2026
The army had wanted to make sure I could remember complicated instructions, in English and in French, while translating information crucial to the war.
From "The Brightwood Code" by Monica Hesse
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.
