back·cross 
(băkkrôs′, -krŏs′)
(băkkrôs′, -krŏs′)tr.v. back·crossed, back·cross·ing, back·cross·es
To cross (a hybrid) with one of its parents or with an individual genetically identical to one of its parents.
n.
1. The act of making such a cross.
2. An individual resulting from such a cross.