Sistafy 

A sister whooping someone's behind on behalf of her sister for the sake of standing up for her beloved sibling

They still haven't posted the contest results. I think you need to go sistafy their behinds!!!

Sistafy by JJ5783 November 1, 2012

Sistaffection 

-noun
1. A non-sexual relationship between two women that are unusually close.
2. Female bromance

Henry: So Julia, whats up with Frances and Sophie?
Julia: I don't know I think they have a real sistaffection going on!

Sistaffection by MichaelSharey August 13, 2013

Sistay 

The term used for someone who stans Stray Kids (KPOP band) but is also a follower of any religion. One that follows Stray Kids must not be an angel, because all Stays are crackheads (Not legit, just joking). Therefore they are automatically a sister. Sister + Stay = Sistay.

Omg Sistay can’t wait for Stray Kids new album!

Looking forward to it sistay!

Sistay by Wthskz January 4, 2019

sistafriend 

A term of endearment between bffs, deaper then a girlfriend relationship.
Someone who is your friend by birth, your sister by choice.

hey sistafriend what ya got going on today?

Sistafriend! Did you hear...

sistafriend by AnjewlnWhite April 23, 2009

sistafran 

When you get excited you can refer to the person you're talking to as Sistafran.

"I am a communist."
"OMG SISTAFRAN! NO WAY, ME TOO!"

sistafran by Mike I May 6, 2005