(fn my-name [] (throw (Exception. "boom")))
[Edited: thanks to jerf for pointing out the inconsistency in a term I used.]
i.e.
(= ((fn factorial [x] (if (<= x 1) 1 (* x (factorial (dec x))))) 5) 120)
[Edited: thanks to jerf for pointing out the inconsistency in a term I used.]