‘倾盆大雨’ literally means 'rain pouring from an overturned basin' — a vivid, idiomatic expression describing extremely heavy, torrential rain. The four characters combine to evoke the image of water cascading uncontrollably: 倾 (to pour or tip over), 盆 (a basin or large container), 大 (big or heavy), and 雨 (rain). This phrase emphasizes intensity and volume, not just duration, and is commonly used in both spoken and written Chinese to describe sudden, powerful downpours.

It functions as a noun and often appears after verbs like 下 (to fall, as in rain), 遇到 (to encounter), or 经历 (to experience). While it carries no formal register restriction, it’s more common in descriptive or narrative contexts than in technical weather reports. Native speakers use it for dramatic effect — for example, when recounting a soaked commute or a flooded street — making it especially useful for storytelling and expressive speech.