According to the Urban Dictionary: An acronym meaning "Be Authentic Never Jeopardize Individuality" made popular to the mainstream public by Sharaya J in the song Banji produced by Missy Elliot So it isn't really a 'word' at all.

If you meant, "Bungee", then: http://en.wikipedia.org/wiki/Bungee_jumping

Where did you hear it? What was the context?