assurance blow Share definition Flag When you blow your nose one more time after getting most of the snot out just to make sure. "I had to do an assurance blow before I threw away the Kleenex in case there was a little bit of snot left." assurance blow by SquidDude May 8, 2019 0 0 Get merch Get the assurance blow mug. Buy Now — $32.95 See more merch