Nearby words

  1. factitiously,
  2. factitive,
  3. factitively,
  4. factive,
  5. factoid,
  6. factor analysis,
  7. factor cost,
  8. factor group,
  9. factor i,
  10. factor ii

Origin of factor

1400–50; late Middle English facto(u)r < Latin factor maker, perpetrator, equivalent to fac(ere) to make, do + -tor -tor

Related forms Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for factor in

factor in


(tr, adverb) mainly US to take account of (something) when making a calculation



an element or cause that contributes to a result
  1. one of two or more integers or polynomials whose product is a given integer or polynomial2 and 3 are factors of 6
  2. an integer or polynomial that can be exactly divided into another integer or polynomial1, 2, 3, and 6 are all factors of 6
(foll by identifying numeral) med any of several substances that participate in the clotting of bloodfactor VIII
a person who acts on another's behalf, esp one who transacts business for another
commerce a business that makes loans in return for or on security of trade debts
former name for a gene
commercial law a person to whom goods are consigned for sale and who is paid a factorage
(in Scotland) the manager of an estate


(intr) to engage in the business of a factor
See also factor in

Derived Formsfactorable, adjectivefactorability, nounfactorship, noun

Word Origin for factor

C15: from Latin: one who acts, from facere to do


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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for factor in
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for factor in




One that contributes in the cause of an action.
A mathematical component that by multiplication makes up a number or expression.
A gene.
A substance, such as a vitamin, that functions in a specific biochemical reaction or bodily process, such as blood coagulation.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for factor in




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 a2 - b2.
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.


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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with factor in

factor in

Figure in, include as a basic element. For example, In preparing the schedule we factored in vacation and sick days. This term comes from mathematics. [Mid-1900s]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.