punch‧bag /ˈpʌntʃbæɡ/ British English, ˈpunching bag American English noun [countable]

1. a heavy leather bag hung from a rope, that is punched for exercise or training

2. a person who is hit, criticized strongly, or blamed, even though they have done nothing wrong:
a young wife whose husband used her as a punching bag

[TahlilGaran] Dictionary of Contemporary English ▲