tirar la toalla

From the traditional signal from a boxer's support staff of throwing such an item into a boxing ring to indicate that the contestant cannot continue the match and is forfeiting to the opponent.

tirar la toalla (first-person singular present tiro la toalla, first-person singular preterite tiré la toalla, past participle tirado la toalla)

1. (idiomatic) to throw in the towel; to give up; to quit

• see tirar

• “arrojar, o tirar, la toalla”, in Diccionario de la lengua española, Vigésima tercera edición, Real Academia Española, 2014