IPA: /ˈdaʊnˌpɔːr/
KK: /ˈdaʊnˌpɔr/
A very heavy and sudden rain.
The downpour caused the streets to flood quickly.
Downpour → It is formed from "down" (from Old English "dūn", meaning downward) and "pour" (from Old French "pourer", meaning to flow or cause to flow). The word "downpour" describes rain that flows down heavily and continuously.
Imagine rain that flows heavily 'down' — that's why a downpour means a heavy rain falling down.
No commonly confused words.