1. incesttuousin*cesttu*ous (?; 135), a. [l. incestuosus: cf. f. incestueux.] guilty of incest; involving, or pertaining to, the crime of incest; as, an incestuous person or connection. ere you reach to this incestuous love, you must divine and human rights remove. -- in*cesttu*ous*ly , adv. -- in*cesttu*ous*ness , n