[yǎn kǒu hú lú]   

掩    口    葫    芦    捂着嘴笑。

掩口葫芦，yǎn kǒu hú lú，基本释义为捂着嘴笑，出自《后汉书·应劭传》。

Put one's hand to one's mouth to hide one's laughter

掩耳偷铃    掩骼埋窆    掩人耳目    掩旗息鼓    掩口葫芦