punching bag
US /ˈpʌn.tʃɪŋ ˌbæɡ/
UK /ˈpʌn.tʃɪŋ ˌbæɡ/

1.
saco de boxeo, punching bag
a heavy bag, usually made of leather or canvas, filled with sand or other material, that is suspended from above and used for punching practice by boxers or other martial artists
:
•
He trains daily with a punching bag to improve his boxing skills.
Él entrena diariamente con un saco de boxeo para mejorar sus habilidades de boxeo.
•
The gym has several different types of punching bags.
El gimnasio tiene varios tipos diferentes de sacos de boxeo.
2.
saco de boxeo, chivo expiatorio, blanco de críticas
a person or thing that is repeatedly subjected to criticism, abuse, or attack
:
•
He became the team's punching bag after a series of losses.
Se convirtió en el saco de boxeo del equipo después de una serie de derrotas.
•
The manager used the new intern as a punching bag for all his frustrations.
El gerente usó al nuevo pasante como saco de boxeo para todas sus frustraciones.