in-and-in

[in-uhnd-in, -uhn-]

adverb

1. repeatedly within the same family, strain, etc..

   to breed stock in-and-in.

in-and-in

adjective

1. (of breeding) carried out repeatedly among closely related individuals of the same species to eliminate or intensify certain characteristics

Word History and Origins

Origin of in-and-in¹

First recorded in 1620–30