X factor

American

[eks fak-ter] / ˈɛks ˌfæk tər /

noun

plural

X factors

an essential quality or feature that is difficult to identify or express.

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.

Another X factor is the reaction of consumers.

From MarketWatch • Apr. 17, 2026

They’re playing redemptive basketball, witness Deandre Ayton finally showing up and proving he is truly the X factor on this team.

From Los Angeles Times • Mar. 18, 2026

"He is the X factor of my team. He has been amazing, scoring in every game. Tonight he sent a message to the rest of the side with the way he ran and fought."

From Barron's • Jan. 9, 2026

Add it all up to the biggest X factor of the final stretch.

From New York Times • Jan. 14, 2024

To turn the key in the lock, to open the door, he must change the physical reality to balance the equation, rather than supply the X factor to keep reality unchanged.

From Eight Keys to Eden by Clifton, Mark

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023