War slang meaning to unleash hell on the enemy. Or used when dropping the flame agent Napalm. (Liquid fire.) See light em up
Ok boys, let's rain hell!

Charlie's up the river, let's rain hell on em!
by Fire_in_the_hole! February 13, 2014
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When Chad makes us play in this fridged rain hell sleet.
"Hey, did you here?"
"Yea, can you f'in beleive this??
Chad's making us play in this fridged rain hell sleet!"
by SlashSaysBooYa December 19, 2008
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