outcross

noun

1. The introduction of unrelated breeding stock to an existing population, especially one which is inbred or homogeneous.

   “Their two sons, Joseph I and Charles VI went still further in their pursuit of an out-cross by both marrying princesses from the Guelph house of Brunswick.”

2. A plant or animal produced by such methods.

verb

1. (transitive)to crossbreed different strains of a plant or animal.