Wiktionary
vb. (context intransitive English) To rain heavily.
WordNet
Usage examples of "pour down".
I am suddenly aware of myself standing thin and upright in a Meadow where everything has flattened itself down and so I lie down hoping to be unnoticed by the storm which rolls up and I am flat on my back looking up when water begins to pour down from the sky.
THE COLD RAIN that seems more like early winter than autumn continues to pour down.
The stream created a break in the foliage that allowed more sunlight to pour down, letting the plants grow much more thickly.
After five minutes of this mock battle the perspiration began to pour down the faces, and the breath to come thick and short.
She pulled the few pins out of her hair, and let red-gold curls pour down about her shoulder and back.
As heated wet air rises above the oceans, cold winds pour down from the Arctic.
Although the motherthing would happily pour down tequila warm, without a drinking glass and condiments, the consequences of allowing her to do so were unpleasant.
Any minute a storm is going to pour down on us mortals and the park.
But the storm had a start on both of them, and before he even got there the rain began to pour down, turning the white dust brown.
The only question I want answered right now is what in the name of Hell did you two pour down your throats to get in this condition?
Indeed, he could imagine it even as he spoke: the bolt of sudden light ripping apart the spout, scattering blazing fluid among the defenders and the open vats which they prepared to pour down on the legion.