adj.用坏的,穿坏的;用旧的,穿旧的;疲惫不堪的;
例句:
The outside corner of the book was worn down.
这本书外面的边角都磨损了.
If the brake pads are worn down they must be replaced.
如果刹车片磨损,必须更换它们.
She'd been worn down by leading a life she wasn't fitted for.
不适宜的生活方式使她衰老.