1.VerbTo bring prosperity or work to an enterprise by selling, inventing or other productive or successful activity.
"It's time to make it rain, my friend!"
2.VerbTo throw a substantial amount of paper money so that it falls on a crowd, audience, performer, or group of performers, often as a way to show off one's wealth.
"John has a propensity to make it rain at parties when he is drunk."
3.VerbUsed other than figuratively or idiomatically: see make, it, rain.
"I asked higher powers to make it rain to save our crops."