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4.
NSI
No Sarcasm Intended;

When you're texting and you say something that isn't meant to be interpreted sarcastically.
Brett: Dude, I got 1st place in the race!
Bruce: Good for you!
Brett: ...
Bruce: NSI
by TextingNSI July 20, 2013
 
1.
Not Sure If Sarcasm. Used when you're not clever enough to know if someone is being sarcastic or not, but you're modest enough to admit it.
A: omg you're awesome. I love u 4ever <33333
B: nsis
A: ... definitely sarcasm
by vicious vaca April 29, 2011
 
2.
NSI
No Sarcasm Intended
used when you make a smart Alec remark when you dont mean to be a smart ass.
That is so sad. i think i wanna cry.

Hm. Smart Ass.

Chill man, NSI
by haleymadeethisss May 06, 2011
 
3.
Nsi
Naval Science Intructor
MSgt. Borland is my NSI. He knows everything.He is a Marine. He is God.
by CPO November 27, 2003
 
5.
Not sure if serious
John: "What's Nsis?"
Bruce: Not sure if serious.
by Not sure if serious June 15, 2014
 
6.
Abbreviation of "Not Sure If Serious"
Mohammed: Cheryl Cole aint even that hot you know
Brandon Nyathi: What? NSIS
by NYATHI09 February 14, 2011
 
7.
Nsi
Damn Brit.
Look at all the pos, especially Nsi.
by Fect February 06, 2003