jiffstard dog Share definition Flag A hot dog with peanutbutter and mustard on it. The combination sounds awful but somehow it works. "Fix me another jiffstard dog, please. And use yellow mustard, not that Gray Poupon like last time." jiffstard dog by Boxsterbeater September 6, 2005 0 0 Get merch Get the jiffstard dog mug. Buy Now — $32.95 See more merch