noun Genetics.

a form of inbreeding directed toward keeping the offspring closely related to a superior ancestor.

Origin of linebreeding

An Americanism dating back to 1875–80; line1 + breeding Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for line breeding

line breeding


selective inbreeding that produces individuals possessing one or more of the favourable characteristics of their common ancestor
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