The idiom "black-and-blue" is used to describe a person or object that has been badly bruised or beaten up. When someone is black-and-blue, it means they have bruises on their body that are typically blue or black in color.
This idiom can also be used to describe a situation that has caused someone emotional pain or distress. For example, if someone says "I was left black-and-blue after that breakup," they mean that the breakup caused them a lot of emotional pain and left them feeling bruised and battered.
Overall, the idiom "black-and-blue" is used to describe physical or emotional pain that has left someone feeling beaten up and bruised.
• My brother got into a fight at school and came home with a black-and-blue eye.
• The victim of the robbery was left black-and-blue from the attack.
• She was black-and-blue with bruises from the car accident.
• After playing soccer for three hours, my knees were black-and-blue.
• I fell down the stairs and now my leg is black-and-blue.
• The boxer's face was black-and-blue after the intense match.