look up any word, like bootylicious:
2. NSIS
Abbreviation of "Not Sure If Serious"
Mohammed: Cheryl Cole aint even that hot you know
Brandon Nyathi: What? NSIS
1. NSIS
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
3. NSIS
No Sky In Sight - A kick as band In Port Angeles, WA, USA
NSIS is bad ass
rss and gcal