Slang: Throw in the towel

Definition: To quit.


Example:
1) The company threw in the towel after losing all of its major customers.


2) Mike 'Boom Boom' DeNola threw in the towel after three rounds. He'll probably have to spend a few days in the hospital, followed by a long convalescence in Miami.


Etymology: This phrase comes from boxing. When a boxer is too beat up to continue, his coach throws a towel into the ring to signal that the fight is over.




fonte: www.peakenglish.com