But what does it mean, though?

4 seconds sound clip from Batman (1966) - Hi Diddle Riddle (S1E1) TV Series.

You can hear this line at 00:05:59 in the Blu-ray version of the movie.

Quote context

[...]

- Can you come to headquarters right away?

- It'll be a pleasure, Commissioner Gordon.

- Atomic batteries to power. Turbines to speed.

- Clear. Ready to move out.

- Why is an orange like a bell?

- Answer: because they both must be peeled! Right.

- You peel an orange and you peal a bell. Get it?

- What idiots we are! Why couldn't we have worked that out?

- But what does it mean, though?

- Right, commissioner. There's a problem.

- We all know how this quizzical criminal operates. He deliberately leaves clues to confound us.

- Clues which may or may not lead to the real crime he's planning.

- The real crime?

- Precisely, Inspector Basch.

- The Riddler contrives his plots like artichokes. You have to strip off spiny leaves to reach the heart.

[...]