knuckle under
knuckle under
v.
darse por vencido
knuckle under (to)
(v.) = desistir, doblegarse, ceder, rendirse, pasar por el aro, claudicar.
Ex: This is what decadence looks like: a frantic coarseness that trashes its own values and then knuckles under swiftly to totalitarianism and brute force.