courtesy sister

A friend(no 'benefits') who's so close she's like a sister, or just is the mother of someone who calls you Uncle. (could be a former sexual partner, but who is only a friend now)

How many siblings do you have?

Well, I have 2 brothers, 2 sisters from my mom, & a half brother from my dad, & a courtesy sister I stilll keep in touch with.

by cyberpope67,BC,Canada May 2, 2021

half-co-sister-in-law

Spouse's half-sibling's wife.

half-co-sister-in-law.

by Simaduria July 27, 2024

Sister-Cousin

Your female cousin whom you are so close with that your relationship reminds you of a loving pair of sisters.

That’s not just my cousin. That is my sister-cousin.

by John Jacob Allen Smith March 5, 2024

boob sister

when you and your friend are wearing the same top or the same color by mistake, you’re boob sisters

oh, look we are wearing the same top…
-I know, we are boob sisters now.

a boob sister is when you and your friend are matching tops by mistake !

by lululune May 9, 2023

sister sis

the prettiest gal ever.

sister sis is so cute omg.

by justdoitNike April 1, 2020

Texas Sister

1.Your thick sibling whom you'd like to fuck.

2. when the girl takes charge when having sex.

2. "Damn I want to get in my Texas sister."
3. "I hate when girls act like a Texas sister."

by gmoney2904 December 8, 2017

Hot sister

Monique (D.A. Sister)

Man, Dave’s sister is hot, see if she will come over.

She’s a hot sister

by Devilbev November 18, 2022