中英成语俚语800对129：反复无常

　　反复无常

　　Play fast and loose.

　　eg：One should not blow hot and cold with what one has promised.

　　中英俚语俗语来源：汉书：“齐夸诈多变，反覆之国。 ”

　　同义词：变幻莫测 The wind keeps not always at one quarter.

　　反义源：矢至不渝 Stick to it.