Nobody knows what it means, they only use it because it'll make them sound really really nerdy and nerds always get the girls as it was shown in revenge of the nerds when the nerds were looking at cheerleader's boobs.
Moral of the story is that ninjas are cooler than pirates.
Erin: "Hey Jason, you ever try decaffeinated coffee? You probably need to lay off the monster too."
Jason: "Don't worry I got that phrase from the inner bowels of my butthole. Otherwise known as Urbandictionary.