Question: what does it mean when someone is making it rain?
Answer: (idiomatic) to 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. Used other than with a figurative or idiomatic meaning: see make,‎ it,‎ rain.