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
City News Service, San Diego Union-Tribune, 11 May 2025
The researchers suggested a biological basis (underlying physical, neurological, or genetic factors) for any association.
—Lana Barhum, Verywell Health, 10 May 2025
Nellie Andreeva, Deadline, 9 May 2025
In a sport where at least half the players are Black, no matter the level of play, how do Black mothers specifically factor in?
—Essence, 9 May 2025
See All Example Sentences for factor
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Noun
According to police, speed and driving under the influence were determined to not be factors in the collision.
—City News Service, San Diego Union-Tribune, 11 May 2025
The researchers suggested a biological basis (underlying physical, neurological, or genetic factors) for any association.
—Lana Barhum, Verywell Health, 10 May 2025
Verb
On a stacked 2024-25 broadcast schedule, Found – like The Irrational – has been registering steep year-to-year ratings declines, which factored in the cancellation decision.
—Nellie Andreeva, Deadline, 9 May 2025
In a sport where at least half the players are Black, no matter the level of play, how do Black mothers specifically factor in?
—Essence, 9 May 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 20 May. 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
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