airbag
n. B1 Intermediate US //ˈɛɹˌbæɡ// UK //ˈeəbæɡ// airbag
n. a bag that fills with air to protect you if you crash. It is usually in a car and opens very quickly when a seatbelt is pulled.
n. a bag of flexible fabric that inflates rapidly with gas to protect a vehicle occupant from injury during a collision. Typically deployed by a sensor that detects a sudden deceleration.
The car's airbag saved the driver's life.
Modern vehicles are equipped with multiple airbags to provide protection for both the front and side seats.
While seatbelts provide the primary restraint, airbags serve as a secondary safety measure by reducing the force of impact against the vehicle's interior surfaces.
From air + bag.