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.
例句
He had been devious and two-faced...他从前向来都是阴险狡猾，口是心非。The scientists saw the public as being particularly two-faced about animal welfare in view of the way domestic animals are treated.鉴于家养动物所受的待遇，科学家认为公众在动物福利的问题上尤为言行不一。
英汉词典释义
adj.
(人)表里不一的,虚伪的
She called her boyfriend a two-faced son of a bitch.她叫她的男友双面王八蛋。
英英词典释义
Adjective
1. 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
2. having two faces--one looking to the future and one to the past;