The phrase "touché" is often used in response to a clever or effective remark made by someone else in a conversation or debate. It is borrowed from the French language and is commonly used in English to acknowledge that the other person has made a good point or countered one's argument effectively. It essentially means "well said" or "you got me there." Here's how it's typically used:
Person A: "Your proposal lacks sufficient evidence to support its claims."
Person B: "Actually, I have several studies here that provide strong evidence."
Person A: "Touché."
In this context, Person A is conceding that Person B has made a valid counterargument. It's a way of acknowledging the strength of the other person's point, even if you don't fully agree with it.