cru·​cial | \ˈkrü-shəl \

Definition of crucial 

1 archaic : cruciform

2a : important or essential as resolving a crisis : decisive She played a crucial role in the negotiations.

b : marked by final determination of a doubtful issue the crucial game of a series

c : important, significant … what use we make of them will be the crucial question.— Stanley Kubrick Vitamins are crucial for maintaining good health.

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Synonyms for crucial


critical, key, pivotal, vital

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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.
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Recent Examples on the Web

These epic journeys, called pre-molt dispersals, are crucial for survival. Gemma Tarlach, Discover Magazine, "20 Things You Didn't Know About ... Penguins," 6 Nov. 2018 There’s a small detail that’s crucial for getting a Sabrina costume right, according to Shipka: her golden locket. Halie Lesavage, Glamour, "Why The Chilling Adventures of Sabrina Is the Perfect Last-Minute Halloween Costume Inspiration," 25 Oct. 2018 Waffle House is so crucial when a storm hits because the 24-hour chain often stays open when the weather gets bad. Megan Friedman, Country Living, "Want to Know If a Hurricane Is Bad? Ask Your Local Waffle House," 13 Sep. 2018 The magnetosphere plays a crucial role in protecting Earth from solar radiation. Meghan Bartels,, "Long-Lost Spacecraft That NASA Rediscovered This Year Is Incommunicado," 30 Aug. 2018 Our customers told us that the comfort of their dogs on car journeys is crucial. Leah Melby Clinton, Town & Country, "This Luxury Auto Brand Is Making Traveling with Your Dogs Easier," 24 Aug. 2018 This issue of maintenance really depends on one crucial factor: cleaning. Nicole Spector /, NBC News, "The kitchen is the germiest room. Here's how to deep clean everything.," 3 July 2018 Many businesses lost power and natural gas, crucial for reopening. Michael Klein,, "Water main break wreaks havoc on Center City restaurants," 3 July 2018 Even though police cameras are becoming more prevalent, eyewitness testimony was crucial in every single case over the past 13 years in which a police officer was convicted by a jury for an on-duty killing. Michael Harriot, The Root, "All Black People Are Victims of Police Brutality," 26 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'crucial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of crucial

1706, in the meaning defined at sense 1

History and Etymology for crucial

French, from Latin cruc-, crux cross

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Dictionary Entries near crucial







crucian carp

Statistics for crucial

Last Updated

4 Dec 2018

Look-up Popularity

Time Traveler for crucial

The first known use of crucial was in 1706

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More Definitions for crucial



English Language Learners Definition of crucial

: extremely important


cru·​cial | \ˈkrü-shəl \

Kids Definition of crucial

1 : being a final or very important test or decision : decisive a crucial battle

2 : very important : significant Water is a crucial element in our weather.

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More from Merriam-Webster on crucial

Thesaurus: All synonyms and antonyms for crucial

Spanish Central: Translation of crucial

Nglish: Translation of crucial for Spanish Speakers

Britannica English: Translation of crucial for Arabic Speakers

Comments on crucial

What made you want to look up crucial? Please tell us where you read or heard it (including the quote, if possible).


a nest or breeding place

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