Crazy, Insane, Amazing, AWESOME Sex/sexual activites that partake between two biffles, or best friends.
Wow, last night was so crazy. I was over her house last night and we ended up biffle bagging. Hey there, fuzzy line between friend zone and bromance.
by ChristoferCraig May 29, 2011

by Dr. Fatz February 2, 2004

a sister who is also a best friend, or a friend who is closer to you than a friend and is more like a sister.
My sister, Kim, is also my best friend; she is my sister-biffle!
I love my friend Kristin so much, we are such good friends that she is more like a sister to me; she is my sister-biffle!
I love my friend Kristin so much, we are such good friends that she is more like a sister to me; she is my sister-biffle!
by BAD1484 May 13, 2010

by emilydawsonx June 21, 2011

Best friends for life forever, when "best friends for life" and "best friends forever" are not enough
"We're not just friends, we're not just best friends, we're not just biffles, we're BIFFLES FORIFFLES."
by Mr. La-Liffle June 25, 2009

A girl that has a big booty along with a cute face and rocking body that can show you the time of your life anywhere and anyway she wants to.
by jay em ay January 1, 2009

Biffle Married is simply the marriage between two best friends. ie. Starsky and Hutch, Harold and Kumar, Chewy and Han. Can also happen bteween opposite sex's.
by cleverman1 June 11, 2012
