sis 

the abbreviation of "sister";
a genderless term much like "bro" or "dude"

people can also say it like "sister" but that doesn't change the definition

like when you say "brother" instead of "bro"

-"How do you feel about celebrity drama?"
-"It's the tea, sis."

-"Hey sisters!" -James Charles

-"How u doing?"
-"I'm so fucking depressed, sister"

sis by Bakuhoe Katsubitch January 9, 2019

sis 

1.) A South African English expression roughly equivalent to the American "yech" and the Afrikaans expression "sies".

2.) An American term of endearment for a sister, now also used in other countries.

1.) Sis, man, you stink!

2.) Hey, sis, hey bro, how's Ma doin'?

sis by Xaviana December 1, 2003

SIS 

a genderless term much like "bro" or "dude"

you don’t have to be BFFS. You don’t really even have to know them. If she seem chill. then SISSSSSS is what they should be called!

JACK: *texts Jill*

“ SIS! You’ll never believe what popped up on Greg’s phone!!”

Jill: “Girl, SPILL!”

Jack: “Some HOE’S NAME! Do you think he is cheating on me?!”

Jill: “ SIS! YES! Leave his ass!”

****you can also use it in less dramatic scenarios****

SIS by URB@NL3GEND March 4, 2020

sis 

short for sister

"HI SISTERS" = james charles

sis by emolay;) June 13, 2018

SIS 

Snickering in Silence
new for LOL because it applies much more than LOL when texting/typing and trying to be quite

While texting in class i received a message with a prime time to say "thats what she said" and/or "reminds me of my saturday night" or even "I get that all the time" so I sis'd vs lol'ing

"idk what happened it just went everywhere after i touched it"
sis
"reminds me of my saturday night"

SIS by kevin "k-bone" December 25, 2009

SiS 

SiS as in Shit Its Sunday Commonly used on sites like Facebook and Myspace

John: Aw man SiS
Kevin: Dude I know

SiS by Kife1100 April 5, 2009

SIS 

Smirk in Silence:
The act of putting on a straight face after putting someone in a spot.
Pulling someone's leg as a group where everyone acts normal in a scenario that is funny.
Used on social networks, chat rooms and forums..at least could be!

Totally loved getting on Spook's nerves acting as if I don't know him at the bar last night. Pulled a SIS.

SIS by far_c November 2, 2009