bum blow Share definition Flag To blow one's nose by pressing down on either nostril and blowing the snot out of the other. Used by people who don't have tissues or are homeless (bums). Whenever I don't have a tissue, I just bum blow to clean my sinuses. bum blow by Prizio February 27, 2004 0 0 Get merch Get the bum blow mug. Buy Now — $32.95 See more merch