Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
inbreeding [ɪnˈbriːdɪŋ] n (among animals) ро́дственное спа́ривание; (among people) узкоро́дственные бра́чные отноше́ния ntpl
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.