The origin of "bumfire" was from a variation on a Shakespeare sonnet by my friend Paul, in relation to another friend, barling. "Shall I compare thee to a khazi, say? Thou art more curried, and more turbulent. Rough winds do shake the Barling cheeks of gay, and bumfire's wrath doth linger in the gents.."
Similar to its bon fire counterpart, a bum fire involves a pollutant-ridden fire cast in an open steel barrel trash can (make up of trash container is flexible), that a multitude of of skeezy homeless personnel can find warmth, scavenging light, or a cooking surface to decoct the day's loot over. Also known as a hobo heater
"Man these hoes be on me like some gutterpups on a bum fire."