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.

---

crucial British  

/ ˈkruːʃəl /

adjective

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

2. informal very important

3. 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

• 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

That makes Saturday’s qualifying and the pit stops in Sunday’s 90-lap race crucial.

From Los Angeles Times • Apr. 16, 2026

The industry had hoped for a recovery this year, driven by better results in crucial markets like the U.S. and China, but the war in Iran has cast a shadow over those expectations.

From The Wall Street Journal • Apr. 15, 2026

Now the government is consulting on the crucial, detailed secondary legislation that would outline enforcement powers and penalties under the Act.

From BBC • Apr. 15, 2026

The Strait of Hormuz long has been known as a crucial energy chokepoint, but the expensive investment needed to bypass the waterway didn’t seem like it was worth the effort.

From MarketWatch • Apr. 15, 2026

At this point the Inquisition stepped in, determined to get their man, and issued the crucial second warning which made the reference to teaching.

From "The Scientists" by John Gribbin

Related Words

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