Other forms: threw in the towel; throwing in the towel
To throw in the towel is to give up. If you're way behind in the 100-yard dash, you can throw in the towel — or you can keep running and feel proud that you finished the race.
When someone throws in the towel, they admit defeat, like a hiker who embarks on the Appalachian Trail only to throw in the towel as soon as they run out of granola bars. This expression comes from boxing slang; when a fighter is clearly overwhelmed by an opponent, their trainer or coach will literally throw a towel into the ring to stop the match. Throw in the towel began being used figuratively by 1915.