Mercy is used to describe a special journey to help someone in great need, such as people who are sick or made homeless by war.
She vanished nine months ago while on a mercy mission to West Africa.
她在9个月前去西非的慈善之旅中消失不见了。
mercies
If someone in authority shows mercy, they choose not to harm someone they have power over, or they forgive someone they have the right to punish.
Neither side took prisoners or showed any mercy.
双方都没有抓俘虏,也没有表现出丝毫的仁慈。
If you refer to an event or a situation as a mercy, you mean that it makes you feel happy or relieved, usually because it stops something unpleasant from happening.
It really was a mercy that he'd gone so rapidly at the end.
他最后走得那么快,这真是一件幸事。
at the mercy of someone
If one person or thing is at the mercy of another, the first person or thing is in a situation where they cannot prevent themselves from being harmed or affected by the second.
Buildings are left to decay at the mercy of vandals and the weather.
这些建筑物因人为的肆意破坏和日晒雨淋而破败不堪。