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1.
A bong made out of a hose, a powerade or gatorade bottle, with a cone piece made out of a can. This is the quintessential Australian Bong.
"Tell Stoss to buy a powerade bottle so we can make a bunji"
by DarbPuncha May 15, 2013
 
2.
close friend, friends for life, my brother
Bella: "Oi, Erica wants to smash you"
Kim: "No way, she my bunji"
by Fifi79 August 25, 2010