Usually a great friend of the opposite sex who you can trust with your life. However, someone who is a biffle is not necessarily stuck in the "friend zone", as biffles often make the best couples. Often, a girl may instigate a biffle relationship as a way of flirting. It is customary to be protective and loyal to your Biffle.
"So is Johnny just your biffle?"
"Yeah, he's just my biffle.. for now..."
"Hey Danny, would you like to be my biffle?"
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