INCESTUOUS Meaning of INCESTUOUS in English [ ɪn'sɛstjʊəs ]■ adjective1》 involving or guilty of incest. 2》 (of human relations) excessively close and resistant to outside influence.Derivatives~ly adverb~ness noun Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004