factor

American  

[fak-ter] / ˈfæk tər /

noun

1. one of the elements contributing to a particular result or situation.

   Poverty is only one of the factors in crime.

2. Mathematics. one of two or more numbers, algebraic expressions, or the like, that when multiplied together produce a given product; a divisor.

   6 and 3 are factors of 18.

3. Biochemistry. any of certain substances necessary to a biochemical or physiological process, especially those whose exact nature and function are unknown.

4. a business organization that lends money on accounts receivable or buys and collects accounts receivable.

5. a person who acts or transacts business for another; an agent.

6. an agent entrusted with the possession of goods to be sold in the agent's name; a merchant earning a commission by selling goods belonging to others.

7. a person or business organization that provides money for another's new business venture; one who finances another's business.

8. factor of production.

9. Scot. the steward or bailiff of an estate.

---

verb (used with object)

1. Mathematics. to express (a mathematical quantity) as a product of two or more quantities of like kind, as 30 = 235, or x 2 − y 2 = (x +y ) (x − y ).

2. to act as a factor for.

verb (used without object)

1. to act as a factor.

verb phrase

1. factor in / into to include as an essential element, especially in forecasting or planning.

   You must factor insurance payments into the cost of maintaining a car.

factor British  

/ ˈfæktə /

noun

1. an element or cause that contributes to a result

2. maths

   1. one of two or more integers or polynomials whose product is a given integer or polynomial

      2 and 3 are factors of 6

   2. an integer or polynomial that can be exactly divided into another integer or polynomial

      1, 2, 3, and 6 are all factors of 6

3. (foll by identifying numeral) med any of several substances that participate in the clotting of blood

   factor VIII

4. a person who acts on another's behalf, esp one who transacts business for another

5. commerce a business that makes loans in return for or on security of trade debts

6. former name for a gene

7. commercial law a person to whom goods are consigned for sale and who is paid a factorage

8. (in Scotland) the manager of an estate

---

verb

1. (intr) to engage in the business of a factor

factor Scientific  

/ făk′tər /

1. One of two or more numbers or expressions that are multiplied to obtain a given product. For example, 2 and 3 are factors of 6, and a + b and a − b are factors of a ² − b ².

2. A substance found in the body, such as a protein, that is essential to a biological process. For example, growth factors are needed for proper cell growth and development.

---

1. To find the factors of a number or expression. For example, the number 12 can be factored into 2 and 6, or 3 and 4, or 1 and 12.

Usage

Factor (sense 1) should only be used to refer to something which contributes to a result. It should not be used to refer to a part of something such as a plan or arrangement; instead a word such as component or element should be used

Other Word Forms

• factorability noun
• factorable adjective
• factorship noun
• subfactor noun
• underfactor noun
• unfactorable adjective
• unfactored adjective

Etymology

Origin of factor

First recorded in 1400–50; late Middle English facto(u)r, from Latin factor “maker, perpetrator,” equivalent to fac(ere) “to make, do” + -tor agent noun suffix; -tor

Explanation

A factor is a part or element that contributes to a result. If you only fly budget airlines and refuse to stay anywhere but youth hostels, then money is probably a big factor in your travel plans. The word factor doubles as both noun and verb. A factor is an element that influences something, like many factors that contribute to global warming. To factor means to consider something relevant when making a decision or conclusion, like factoring in the weather and traffic when figuring out how long the drive will be. And if it's not relevant? Then you factor it out.

Example Sentences

Cost of living remains the most important factor in determining residents’ quality of life, a measure that fell from 2025 rankings, the survey found.

From Los Angeles Times • Apr. 16, 2026

A major factor in recent years was demand from Indonesia, where the fast-growing battery industry is a big consumer of sulfuric acid, according to Sarah Marlow, head of fertilizer pricing at Argus.

From The Wall Street Journal • Apr. 16, 2026

Aging is not the only factor behind this buildup.

From Science Daily • Apr. 16, 2026

Crucially, this in turn would massively help governments reduce their interest expense because bond markets are obliged to factor in risk aversion because they are focused on second-guessing inflation three months out.

From MarketWatch • Apr. 15, 2026

But there was no dealing with the wizard, and slowly, again, the deadly Cliffs became a factor in the fight, only now it was the man in black who was being forced to doom.

From "The Princess Bride" by William Goldman

Related Words

• aspect
• cause
• circumstance
• component
• consideration
• element
• influence
• ingredient
• part
• point
• thing