tarnish

Definition

To lose shine or luster, especially through superficial damage or exposure; to make something dull or less impressive.

中文 失去光泽或光彩，尤其是因表面损伤或暴露；使某物变得暗淡或不那么令人印象深刻。

Example

"The silver spoon began to tarnish after being left in the air for months."