Definitions by I'mwhatsup(:

That's whats up 

Used to agree with something, To say you like something, When you don't know what else to say, and when you don't know how to answer a text.

-I'll be there later.
-That's whats up.

-So, I'm bored.
-That's whats up.

-Wanna get burritos?
-That's whats up!!

That's whats up by I'mwhatsup(: February 11, 2010