TRAITOR Meaning of TRAITOR in English ■ noun a person who betrays their country, a cause, a person, etc.Derivatives~ous adjective~ously adverb OriginME: from OFr. traitour , from L. traditor , from tradere 'hand over'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004