noun Biology.

the mating of closely related individuals, as cousins, sire-daughter, brother-sister, or self-fertilized plants, which tends to increase the number of individuals that are homozygous for a trait and therefore increases the appearance of recessive traits.

Origin of inbreeding

First recorded in 1835–45; inbreed + -ing1


[in-breed, in-breed]

verb (used with object), in·bred, in·breed·ing.

to breed (individuals of a closely related group) repeatedly.
to breed within; engender.

verb (used without object), in·bred, in·breed·ing.

to engage in or undergo inbreeding.

Origin of inbreed

First recorded in 1590–1600; in-1 + breed Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for inbreeding

Contemporary Examples of inbreeding

Historical Examples of inbreeding

  • Inbreeding, caponizing, etc., What to do at different seasons.

    Apple Growing

    M. C. Burritt

  • It is very probable, but not absolutely certain, that inbreeding is harmful.


    William Graham Sumner

  • The notion of harm in inbreeding has spread all over the earth.


    William Graham Sumner

  • Inbreeding maintains the excellence of a breed at the expense of its vigor.


    William Graham Sumner

  • Inbreeding intensifies and fixes the qualities, be they good or bad.

    Hints on Dairying

    T. D. Curtis

British Dictionary definitions for inbreeding


verb -breeds, -breeding or -bred

to breed from unions between closely related individuals, esp over several generations
(tr) to develop within; engender
Derived Formsinbreeding, noun, adjective
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 inbreeding

c.1842, from in + breeding.

Online Etymology Dictionary, © 2010 Douglas Harper

inbreeding in Medicine




The continued breeding of closely related individuals so as to preserve desirable traits in a stock.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

inbreeding in Science



The breeding or mating of related individuals within an isolated or closed group of organisms or people. Inbreeding can result in inbreeding depression. However, in agriculture and animal husbandry, the continued breeding of closely related individuals can help to preserve desirable traits in a stock.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.