make it rain
v. phr.— «If that’s not enough, showoffs at Rehab have developed a custom that they call making it rain. “They drop $100 bills from the cabanas up above,” Mr. Pallas says, “and watch the crowd down below go crazy. We have a guy come in every Sunday on his private jet. He stays for the day and makes it rain.”» —“Losing Your Shirt, but Not in the Casino” by Michael Kaplan in Las Vegas New York Times Aug. 26, 2007. (source: Double-Tongued Dictionary)