named for the metaphor of bringing a cannon (like a small civil war cannon) to a party to do one of two things
1. Pulled when someone says something toolish
2. Used to disperse a crowd in a bar of people you don't like.
1. Sam and Rick outside during smoke break
Sam: Hey Rick, it's your birthday coming up and we should celebrate. let's do something cool; we'll make it a party
Rick: No can do, I have some work to do. Anyway, I really enjoy work and think get-togethers are getting sort of old, you know?
Sam: *imitates pulling the draw string of a cannon* Party Cannon! That is the lamest toolish
piss I've ever heard. Take your head out of your ass and let's go celebrate your fuckin' birthday.
2. Paul: Joe pulled out the party cannon when the Stamp collectors association started singing at his favorite bar. It dispersed them, and then Joe and his friends could drink and have a good time in peace.