“Throw in the towel” comes from boxing. In a match, a fighter’s trainer or corner team could toss a towel into the ring to signal that the fight should stop. This meant the fighter was being withdrawn, usually to prevent more punishment.
Over time, the phrase moved into everyday English. Now it means to quit, give up, or admit defeat in almost any kind of situation, not just sports.
- Original boxing use: “The boxer was exhausted, so his coach threw in the towel.”
- Everyday use: “After three failed attempts, they threw in the towel on the plan.”
This is a good example of how sports language often becomes part of general speech. Even people who know nothing about boxing still understand the phrase as meaning that someone has decided to stop trying.
A close idea is give up, but “throw in the towel” often sounds a little more vivid because it suggests a clear moment of surrender.