To produce (an organism) by the mating of individuals of different breeds, varieties, or species; hybridize.
Recalling the crossbreeding of the lakeside daisy, he insists, "If we hadn't polluted that population with Ohio plants it might have vanished.1988 April 15, James Krohe Jr., “Where Has All the Flora Gone?”, in Chicago Reader:
2
To mate so as to produce a hybrid; interbreed.
3
To mate (an organism) with another organism so as to produce a hybrid.
An organism produced by mating of individuals of different varieties or breeds.
When I ask about these dogs, they are described to me as the local mutts, mongrels, pavement specials, crossbreeds.2001, Raymond Coppinger, Lorna Coppinger, Dogs, page 69: