It’s a slang word I’m fond of using, but sometimes draws blank stares. Based on the Urban Dictionary (see here and here), spitballing involves any or all of the following:
• tossing ideas around with little expectation of them coming to pass
• making harmless jibes or attacks; making weak accusations
• suggesting loosely, often going against common logic
• shooting ideas out in the open, potentially causing oneself to look like a dunce
The Busybody 