spare part

US /ˈsper pɑːrt/
UK /ˈsper pɑːrt/
"spare part" picture
1.

備用零件, 備件

a duplicate part of a machine or vehicle kept in reserve in case of need

:
Always carry a spare part for your bicycle.
自行車要常備備用零件
The mechanic ordered a new spare part for the car engine.
機械師為汽車發動機訂購了一個新的備用零件