English▸ verb [with object] cross (a hybrid) with one of its parents or an organism with the same genetic characteristics as one of the parents:
(as adjective backcrossed) after five generations the backcrossed dogs were indistinguishable from purebred dalmatians
[no object] they backcrossed with red-flowered parents to reinforce the effect.
▸ noun an instance or result of backcrossing.