Lewis & Short

bĭgĕner, ĕra, ĕrum, adj. [bis-genus, like degener from de-genus, and bicorpor from bis-corpus], descended from two different races, hybrid, mongrel, Paul. ex Fest. p. 33, 14 Müll.: muli et hinni bigeneri atque insiticii, Varr. R. R. 2, 8, 1.