a. Not procreating or breeding freely; as, one race may be dysgenesic with respect to another. Darwin. [ 1913 Webster ]

‖n. [ Pref. dys- + genesis. ] (Biol.) A condition of not generating or breeding freely; infertility; a form of homogenesis in which the hybrids are sterile among themselves, but are fertile with members of either parent race. [ 1913 Webster ]