a back rest.

• 靠背

a back rest.的用法和样例：

例句

1. Please put the back of your seat in an upright position.
   请把座位靠背转到垂直位置。
2. The congenial singer's laid back demeanor is at odds with his current wired state.
   他惬意地靠在沙发靠背上的姿势与他目前这种兴奋的状态不怎么一致。