spare part
US /ˈsper pɑːrt/
UK /ˈsper pɑːrt/

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。