factorial

adjective
fac·​to·​ri·​al | \ fak-ˈtȯr-ē-əl How to pronounce factorial (audio) \

Definition of factorial

 (Entry 1 of 2)

: of, relating to, or being a factor or a factorial

factorial

noun

Definition of factorial (Entry 2 of 2)

1 : the product of all the positive integers from 1 to n symbol n!
2 : the quantity 0! arbitrarily defined as equal to 1

Examples of factorial in a Sentence

Recent Examples on the Web: Noun Here’s one easy way to construct a list of, say, 100 composite numbers in a row: Start with the numbers 2, 3, 4, … , 101, and add to each of these the number 101 factorial (the product of the first 101 numbers, written 101!). Quanta Magazine, "Prime Gap Grows After Decades-Long Lull," 10 Dec. 2014

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

First Known Use of factorial

Adjective

1837, in the meaning defined above

Noun

1869, in the meaning defined at sense 1

History and Etymology for factorial

Adjective

factor entry 1 + -ial (in mathematical sense after French factoriel)

Noun

borrowed from French factorielle, noun derivative from feminine of factoriel factorial entry 1

Keep scrolling for more

Learn More about factorial

Time Traveler for factorial

Time Traveler

The first known use of factorial was in 1837

See more words from the same year

Statistics for factorial

Cite this Entry

“Factorial.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/factorial?pronunciation&lang=en_us&dir=f&file=factor07. Accessed 28 January 2020.

More from Merriam-Webster on factorial

Rhyming Dictionary: Words that rhyme with factorial

Britannica.com: Encyclopedia article about factorial

Comments on factorial

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

WORD OF THE DAY

showing steady, earnest care and effort

Get Word of the Day daily email!

Test Your Vocabulary

Intact Latin Quiz

  • roman tablet
  • What did focus mean in Latin?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Add Diction

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!