Bum rap is an idiom that means a false accusation or conviction; also, unfair criticism or action. It originated in the 1920s as underworld slang. By the 1950s the term was also used figuratively for other kinds of injustice.
The term bum rap is also a popular pun and phrase in spanking-related context: bum is a synonym for the buttocks and rap means to hit sharply and swiftly. It is most commonly encountered in anti-spanking activist context to express that spanking children is wrong and unfair.
Related expressions are:
- To take the rap means to accept blamed or punished unfairly for something you have not done. This is often implies an active attempt to protect the real guilty party. Sometimes the only unfair part is from taking sole responsibility to let accomplice get away scot-free
- To beat the rap means to avoid being punished.
- A rap across/on/over the knuckles means a punishment which is not very severe but which warns you not to behave that way again.