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.
by Prizio February 27, 2004
1 more definition
a fart, or pass wind, often reffered to as a person who is as valueable as passing wind
e.g. billy bob is such a bumblow
by vinstar November 04, 2005