The Slope of a Vertical Line Share definition Flag Infinity, or a very large, unquantifiable number. "Dude, how rich is Bill Gates? His bank statements much be, like, the slope of a vertical line." The Slope of a Vertical Line by yequalsmxplusb February 12, 2009 0 0 Get merch Get the The Slope of a Vertical Line mug. Buy Now — $32.95 See more merch