Si

1. Spanish for "yes".

2. Abbreviation for "suck it!"

3. Abreviatiin for "self injury"

Wy don't u si!

by Bojojo July 5, 2011

SI

1. Spanish for "yes."
2. Misspelling of "is."

1. "I suck." "Si."
2. "NO YUO FAGOT A COMPUTAR SI NOT A HAT!"

by Dj gs68 September 22, 2003

SI

self-injury

I haven't SI'd in two weeks.

by Anonymous Ex-cutter June 21, 2003

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"

by kevin "k-bone" December 25, 2009

SI

SI is the abbr. of stupid idiot , although it can also be used in a way in which it means mug

I.E. billy you fucking si, si does not mean sigh which means you bore.

by jake lowe February 11, 2008

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.

by far_c November 2, 2009

SIS

suck it slow

i want you to SIS

by foonster March 8, 2010