The Japanese misspelling of laugh. This is because they don't have an L in any of their alphabets. Also if they were to pronounce it slowly it would soundlike laugh instead of raugh.
A response to show compassion when your friend starts talking about how terrible his life is, often using extreme examples that no one else could relate to.
Person A: My car broke down, I lost my job, and my dog died all in one week!
Person B: Damn... that's rough, buddy.
Sokka: My first girlfriend turned into the moon.
Zuko: That's rough, buddy.