- penalty box (def. 1).
- an isolated room or facility where offenders, as misbehaving students or disruptive prisoners, are placed for a period of detention or rehabilitation: secondary-school cyberbullies sent to the sin bin; four inmates doing time in the sin bin for physical violence.
- (in ice hockey, rugby, etc) an area off the field of play where a player who has committed a foul can be sent to sit for a specified period
- a special unit on a separate site from a school that disruptive schoolchildren attend until they can be reintegrated into their normal classes
