A number so large it can only be found on Urban Dictionary.  Mass quantities. Lots of certain stuff.  Represented by a 1 followed 461 billion zeros.
> Moe: So, Joe.  What are your plans for the weekend?
> Joe: Why Moe, I'm gunna try to drink a thrillion beers by Sunday night.
> Moe: Good luck, Joe.  You're a true American hero!