marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another; "she was a deceitful scheming little thing"- Israel Zangwill; "a double-dealing double agent"; "a double-faced infernal traitor and schemer"- W M Thackeray
disapproval If you describe someone as two-faced, you are critical of them because they say they do or believe one thing when their behaviour or words show that they do not do it or do not believe it. He had been devious and two-faced. changing what you say according to who you are talking to, in a way that is insincere and unpleasant - used to show disapproval
having two faces--one looking to the future and one to the past; "Janus the two-faced god"