The act where two sisters, typically twins, avoid all altercations with their friends in order to spend quality time together.
Friend: "Hey, do you twins want to hang out"
Sister1: "Sorry we can't"
Sister2: "Yeah, go away. We need to go Sister Bonding"
Sister1: "Sorry we can't"
Sister2: "Yeah, go away. We need to go Sister Bonding"
by Baes rocker May 31, 2016

by peacelovejuice October 6, 2016

Friends who are sisters, but more. They are alike in almost every way! They don't have to necessarily look alike.
by meyoutwinning July 14, 2015

She is a character from the show Adventure Time and is first introduced in the mini-series "Stakes". The Moon, also called Sister Moon, is one of the 5 vampire's in the Vampire king's court.
To put it simply, she is the best vampire to ever exist in the world of monsters in all universes. Even Lady Dimitrescu's got nothing on her. Maybe. I'm not sure.
To put it simply, she is the best vampire to ever exist in the world of monsters in all universes. Even Lady Dimitrescu's got nothing on her. Maybe. I'm not sure.
by SuspiciouslySweetSubstance July 7, 2021

by midati June 4, 2020

A relationship that appears to be in harmony on the surface, yet in fact both people hate each other or trying to compete with another in secret. Plastic sisters get jealous of each other yet maintain a formal smile all the time. Not particularly girls.
Look, A and B are obviously plastic sisters.
Why are they still together, A’s bf cheated on her with B?
That’s literally what plastic sisters mean.
Why are they still together, A’s bf cheated on her with B?
That’s literally what plastic sisters mean.
by PG One May 31, 2018

A cult of lacrosse playing girls who wear black scrunches. Upon imitation they are taught the lax girls handshake, and the position is for life and after.
“Where is your black scrunchie” -Carolynn
“Right here, I know it’s a huge problem to forget the iconic scrunch as a lax sister” -maddie
“Right here, I know it’s a huge problem to forget the iconic scrunch as a lax sister” -maddie
by Croatian_boi February 18, 2018
