1
: one who acts or transacts business for another: such as
a
b
: one that lends money to producers and dealers (as on the security of accounts receivable)
2
a(1)
: one that actively contributes to the production of a result : ingredient
price wasn't a factor in the decision
(2)
: a substance that functions in or promotes the function of a particular physiological process or bodily system
a clotting factor that facilitates blood coagulation
b
: a good or service (such as land, labor, or capital) used in the process of production
3
: gene
4
a
: any of the numbers or symbols in mathematics that when multiplied together form a product (see product sense 1)
also
: a number or symbol that divides another number or symbol
b
: a quantity by which a given quantity is multiplied or divided in order to indicate a difference in measurement
costs increased by a factor of 10
factored; factoring
ˈfak-t(ə-)riŋ 
: to work as a factor
1
: to resolve into factors
2
a
: to include or admit as a factor
—used with in or into
factor inflation into our calculations
b
: to exclude as a factor
—used with out
Did you know?
In Latin factor means simply "doer". So in English a factor is an "actor" or element or ingredient in some situation or quantity. Charm can be a factor in someone's success, and lack of exercise can be a factor in producing a poor physique. In math we use factor to mean a number that can be multiplied or divided to produce a given number (for example, 5 and 8 are factors of 40). And in biology a gene may be called a factor, since genes are ingredients in the total organism.
Examples of factor in a Sentence
Noun
There were several factors contributing to their recent decline.
Poor planning was a major factor in the company's failure.
6, 4, 3, and 2 are factors of 12.
Verb
you should factor in inflation in making investment decisions
Recent Examples on the Web
Jamie Lang, Variety, 27 June 2025
Three key factors make this particularly hard and point to where solutions might emerge.
—Jeff Mahler, Forbes.com, 27 June 2025
Scott Cohn, CNBC, 27 June 2025
But that total only took into account direct spending, according to the US Travel Association, which estimates Swift’s total impact likely exceeded $10 billion when factoring in indirect spending and when non-ticket holders make purchases outside of venues.
—Auzinea Bacon, CNN Money, 27 June 2025
See All Example Sentences for factor
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Noun
Anime’s influence among athletes, particularly Black and African audiences, was a motivating factor in the collaboration, according to the partners.
—Jamie Lang, Variety, 27 June 2025
Three key factors make this particularly hard and point to where solutions might emerge.
—Jeff Mahler, Forbes.com, 27 June 2025
Verb
Because international trade is so important to so many states, CNBC is factoring the potential risks from tariffs into our annual state competitiveness rankings, America’s Top States for Business.
—Scott Cohn, CNBC, 27 June 2025
But that total only took into account direct spending, according to the US Travel Association, which estimates Swift’s total impact likely exceeded $10 billion when factoring in indirect spending and when non-ticket holders make purchases outside of venues.
—Auzinea Bacon, CNN Money, 27 June 2025
See All Example Sentences for factor
Cite this Entry
“Factor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/factor. Accessed 11 Jul. 2025.
Copy CitationKids Definition
factor
1 of 2 noun
fac·tor
ˈfak-tər
1
: one that buys or sells property for another : agent
2
: something that contributes to the production of a result
price wasn't a factor in our decision
3
: gene
4
: any of the numbers or symbols in mathematics that when multiplied together form a product
especially
: a number that divides another number without leaving a remainder
the factors of 6 are 1, 2, 3, and 6
factor
2 of 2 verb
factored; factoring
-t(ə-)riŋ
1
: to find the mathematical factors of and especially the prime mathematical factors
2
: to act as a factor
attendance will factor into your grade
Love words? Need even more definitions?
Merriam-Webster unabridged
Share