seat belt

1. N-COUNT A seat belt is a strap attached to a seat in a car or an aircraft. You fasten it across your body in order to prevent yourself being thrown out of the seat if there is a sudden movement or stop. (汽車、飛機(jī)座椅上的) 安全帶

The fact I was wearing a seat belt saved my life. 我系著安全帶，幸免于難。