Burntash Share definition Flag A Moustach that connects all the way to the sideburns without a gap, usually regarded as a handlebar moustache. That gap toothed hillbilly has one hell of a burntash! Burntash by fantasticallyfilthy May 25, 2011 0 0 Get merch Get the Burntash mug. Buy Now — $32.95 See more merch