Brown Runway Share definition Flag the brown smudge left by faecal matter in various places, such as a chodbin, your pants, or a womans cleavage. "OH CHRIST! Malcolms done a reverse dogan and left a brown runway all the way down!" Brown Runway by Mr. Flibble & Gopher_By_Fender May 12, 2006 0 0 Get merch Get the Brown Runway mug. Buy Now — $32.95 See more merch