Throw in the towel Informal

To give up on an effort or admit defeat, especially after a long struggle.

It’s used for anything from sports to relationships to business ventures, whenever someone stops trying rather than continue against difficult odds.

The idiom comes from boxing, where a fighter’s cornermen would throw a towel (or, in the older version, a sponge) into the ring to signal that their fighter could not continue and to stop the fight. The sponge version, “throw up the sponge,” is the older form, documented in prizefighting slang from around 1860, referencing the sponges used to wipe down a boxer’s face between rounds; “throw in the towel” is a later variant that emerged as towels came to serve the same practical purpose in a boxer’s corner, and it eventually overtook “sponge” as the dominant form in modern English.

After three failed attempts, he finally threw in the towel.

The company threw in the towel and shut down the project.

Don’t throw in the towel now, you’re so close to finishing.

A: Are you still trying to fix it? B: No, I’m throwing in the towel.