seatbelt
n.a strong strap in a car or plane that you fasten across your body to keep you safe if there is an accident.
n.a safety strap designed to secure a passenger in a vehicle or aircraft, preventing injury during a collision or sudden stop.
“Please fasten your seatbelt before we start the car.”
“The flight attendant walked through the cabin to ensure every passenger had their seatbelt securely buckled for takeoff.”
“Modern automotive safety systems rely on the seatbelt to keep the occupant in the correct position for the airbag to deploy effectively during an impact.”
Commonly used with the verbs 'fasten', 'buckle', or 'wear'.
When using 'put', the particle 'on' is required; otherwise, use the single verb 'fasten'.
seat + belt
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.