The first two characters, 未雨 (wèi yǔ), are straightforward: “not yet rain” or “before it rains.” The last two, 绸缪 (chóumóu), are a classical term meaning “to bind up tightly” or “to repair.” Imagine using silk threads to securely mend something. Together, the idiom paints a clear picture: Before the rain comes, you bind and repair your house. This literal image extends metaphorically to any situation where foresight and preparation can prevent future hardship.