a form of inbreeding directed toward keeping the offspring closely related to a superior ancestor.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
British Dictionary definitions for 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