Rachel and Phoebe take self-defense classes. Ross, who had previously practiced kara-tay tries to attack them by surprise and convince them that they lack unagi, supposedly a state of "total awareness"
Ross: Look, I studying kara-tay for a long time,
and there's a concept you should really be familiar with. It's what
the Japanese call (he holds two fingers up to his temple, and he does
this every time he says this word) unagi.
Rachel: Isn't that a kind of sushi?
Ross: No, it's a concept!
Phoebe: Yeah it is! It is! It's freshwater eel!
Ross: All right, maybe it means that too.
Rachel: Ohh! I would kill for a salmon skin roll right now!
Ross: Y'know what? Fine! Get attacked! I don't even care!
Phoebe: (deadpan) Come on Ross. We're sorry. Please tell us what it is.
Ross: Unagi is a state of total awareness. Okay? Only by achieving true
unagi can you be prepared for any danger that may befall you!
Phoebe: You mean in case someone is trying to steal your bamboo sleeping
mat or your kettle of fish?
so what do you think unagi means?

Congratulation to The Creeds for another FTF!