crucial
Americanadjective
-
involving an extremely important decision or result; decisive; critical.
a crucial experiment.
- Synonyms:
- significant, essential, vital, momentous
-
severe; trying.
-
of the form of a cross; cross-shaped.
adjective
-
involving a final or supremely important decision or event; decisive; critical
-
informal very important
-
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
Derived 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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Jim Burke's Academic Vocabulary List
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Walk Two Moons
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
Slaven said the VA “is building up crucial infrastructure required to handle an increased veteran population.”
From Los Angeles Times • Jun. 10, 2026
Infrastructure investing extends beyond data centers, with private capital increasingly crucial for $106 trillion global needs by 2040.
From Barron's • Jun. 10, 2026
Memory chip makers are ramping up production facilities to address the supply crunch, and that bodes well for another crucial part of the chip industry.
From MarketWatch • Jun. 9, 2026
As Lionel Messi’s Argentina prepared its World Cup defense, team officials quietly traveled to the U.S. on a crucial mission.
From The Wall Street Journal • Jun. 9, 2026
Digby, a friend of Hobbes and a founding member of the Royal Society, played a crucial role in popularizing the word ‘fact’.
From "The Invention of Science" by David Wootton
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.
