What I meant is that functional in this situation is a bit vague.

Clojure Dude (talking to ruby dude): Hey, you should try clojure.

Ruby Dude: What is clojure ?

Clojure Dude: Oh, clojure is a lisp/functional language. You should really give it a try.

Ruby Dude: Why?

Clojure Dude: Its main advantage is that it's functional.

Ruby Dude: Wow, you convince me. I'm switching!