/'mɜ:sɪ; `mɝsɪ/
n
1 [U] kindness, forgiveness, restraint, etc shown to sb one has the right or power to punish 仁慈; 宽恕; 宽容
*They showed mercy to their enemies. 他们对敌人很仁慈.
* We were given no/little mercy. 我们没有得到宽恕.
* He threw himself on my mercy, ie begged me to show mercy. 他求我宽恕他.
* a tyrant without mercy 无情的暴君.
2 [C usu sing 通常作单数] (infml 口) event to be grateful for; piece of good luck 恩惠; 幸运
*It's a mercy she wasn't hurt in the accident. 她在事故中未受伤, 真幸运.
* His death was a mercy, eg He was in such pain that it was best that he died. 他的死是一种解脱（与其痛苦不如一死）.
3 (idm 习语) at the mercy of sb/sth in the power of sb/sth; under the control of sb/sth 任由某人[某事物]摆布或控制
*The ship was at the mercy of the storm, ie out of control or helpless. 那只船在暴风雨中失去控制. be grateful/thankful for small mercies => small. an errand of mercy => errand. leave sb/sth to the mercy/mercies of sb/sth => leave1. throw oneself on sb's mercy (fml 文) beg sb to treat one kindly or leniently 恳求某人善待或宽恕.

interj (dated 旧) (used to express surprise or (pretended) terror 用以表示惊讶或（故作的）惊恐)
*Mercy (on us)! What a noise! 天哪! 多吵闹哇!

n
[Date: 1100-1200; Language: Old French;Origin: merci, from Latin merces 'price paid, payment for work', from merx 'things for sale']
[U]
if someone shows mercy, they choose to forgive or to be kind to someone who they have the power to hurt or punish
　He showed no mercy to his enemies.
　God have mercy on his soul.
beg/cry/plead for mercy
　The boy was screaming and begging for mercy.
at the mercy of sb/sth
unable to do anything to protect yourself from someone or something
　After the boat's motor failed, they were at the mercy of the weather.
　She was completely at his mercy.
mercy flight/mission etc
a journey taken to bring help to people
　a mercy mission to help homeless refugees
leave sb to sb's (tender) mercies
to let someone be dealt with by another person, who may treat them very badly or strictly - used humorously
throw yourself on sb's mercy
to ask someone to help you or forgive you when you are in a very bad situation
it's a mercy (that)
spoken used to say that it is lucky that a worse situation was avoided
　It's a mercy the accident happened so near the hospital.
→be thankful/grateful for small merciesatsmall¹ (13)