go cap in hand从字面意思来看，这个短语是“把帽子拿到手里”，实际意思是“毕恭毕敬；低声下气；摇尾乞怜”。

【例句】
Circumstances once forced him to go cap in hand to the boss for help.
过去他曾不得不低声下气地去向老板求助。

I don't have enough money for rent this month, so I guess I'll just have to go cap in hand to my parents.
我这个月没有足够的钱付房租，所以我想我只能向我的父母寻求帮助了。