Parking-Brake Share definition Flag A boner that you get while sitting down that makes it rather difficult to stand up. Awh man! I tried standing up to go to the bathroom second period, but my parking-brake was on. Parking-Brake by Theworddumpster November 21, 2009 0 0 Get merch Get the Parking-Brake mug. Buy Now — $32.95 See more merch