DBF Share definition Flag Designated Butt Finger- The one finger you use for all your butt upkeep needs, scratching an itch, picking out residual poo etc. Tom: Get your finger out of my face it reeks!Bryan: Calm down that's just my DBF. DBF by brysizzle69 June 9, 2011 0 0 Get merch Get the DBF mug. Buy Now — $32.95 See more merch