In·cest·tu·ous a.
  1. Guilty of incest; involving, or pertaining to, incest; as, an incestuous person or connection.
  Ere you reach to this incestuous love,
  You must divine and human rights remove.   --Dryden.
  -- In*cest*tu*ous*ly, adv. -- In*cest*tu*ous*ness, n.
  ◄ ►