(n.) A pouring or streaming downwards; esp., a heavy or continuous shower.

affluence afflux affluxion brash burst of rain cascade cataract chute cloudburst collapse comedown concourse confluence conflux course crash crosscurrent current debacle declension declination defluxion deluge descending descension descent down downbend downcome downcurve downfall downflow downgrade downrush downtrend downturn downward trend drencher drift driftage drop dropping fall falling flood flow flowing fluency flux gravitation gush gushing rain heavy rain inclination inflow inundation mill run millrace monsoon onrush onward course outflow plash plummeting pounce pour race rainburst rainspout rainstorm rapids run rush scud set soaker soaking rain spate spout stoop stream surge swoop thunderstorm tide torrent torrent of rain trend undercurrent undertow water flow waterfall waterspout