The word "touche" is used to acknowledge a clever or effective point made by someone else, particularly in a debate or conversation. It comes from the French word meaning "touched," and it's often used in situations where you concede that someone has made a valid point, often with a sense of admiration or respect.
The term "touche" originated from the French word 'toucher,' which means 'to touch.' It is often used in fencing to indicate a successful hit, and has been adopted into English to signify an acknowledgment of a valid argument or retort.