Adverb
by incest
Source: WordNetincestuously conceived Source: Internet
Following Pachacuti, the Sapa Inca claimed descent from Inti, who placed a high value on imperial blood; by the end of the empire, it was common to incestuously wed brother and sister. Source: Internet
Nevertheless, 43% of broods produced by incestuously paired females contained extra pair young. Source: Internet