• synonyms


  1. Biochemistry. any of various organic or inorganic substances necessary to the function of an enzyme.
  2. Mathematics.
    1. a prefactor or postfactor.
    2. the product of the minor of a given element of a matrix times −1 raised to the power of the sum of the indices of the row and column crossed out in forming the minor.
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Origin of cofactor

First recorded in 1935–40; co- + factor
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for cofactor


  1. maths a number associated with an element in a square matrix, equal to the determinant of the matrix formed by removing the row and column in which the element appears from the given determinantSee minor
  2. biochem a nonprotein substance that forms a complex with certain enzymes and is essential for their activity. It may be a metal ion or a coenzyme
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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

cofactor in Medicine


  1. A substance, such as a metallic iron or coenzyme, that must be associated with an enzyme for the substance to function.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

cofactor in Science


  1. A substance, such as a metallic ion or a coenzyme, that must be associated with an enzyme for the enzyme to function. Cofactors work by changing the shape of an enzyme or by actually participating in the enzymatic reaction.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.