siding

1. N-UNCOUNT Siding is a wooden, plastic, or metal covering on the outside walls of a building. (建筑外墻木制、塑料制或金屬制的)壁板[美國英語]

2. N-COUNT A siding is a short railway track beside the main tracks, where engines and cars are left when they are not being used. (鐵路線的)側線