不顯山不露水 [ㄅㄨˋ ㄒㄧㄢˇ ㄕㄢ ㄅㄨˋ ㄌㄨˋ ㄕㄨㄟˇ; bu4 xian3 shan1 bu4 lu4 shui3] lit. to not show the mountain and to not reveal the water (idiom); fig. to hide the key facts ◄ ►