Coachblow Share definition Flag A coachblow is the act of closing one nostril to blow out the contents of the other nostril. A coachblow almost always releases a snot rocket. This generally occurs among men of a certain age. Coachblow by stevegarveyfan July 8, 2011 0 0 Get merch Get the Coachblow mug. Buy Now — $32.95 See more merch