1. compassionate or lenient treatment of someone over whom one has some power, as through the administration of justice.
After the war, the former enemy treated the vanquished people with mercy.
2. kind and compassionate treatment of those who are suffering.
Nurses continue to carry out their mission of mercy in the devastated region.
3. an act of mercy, or the tendency to be merciful.
She thanked the judge for his mercy on behalf of her husband.
4. something to be thankful for; blessing.
It was a mercy that the tornado struck just outside of town.