NOXIOUS Meaning of NOXIOUS in English [ 'nɒkʃəs ]■ adjective harmful, poisonous, or very unpleasant.Derivatives~ly adverb~ness noun OriginC15: from L. noxius (from noxa 'harm') + -ous . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004