Uh, no, sir. Grammar. The sentence was grammatically incorrect.

6 seconds sound clip from Batman (1966) - Batman Is Riled (S1E6) TV Series.

You can hear this line at 00:09:51 in the Blu-ray version of the movie.

Quote context

[...]

- Holy grammar! Is that all?

- He who laughs last, laughs best, not good. Best. Best! Best!

- Do you suppose blindfold might have something to do with it?

- Uh, if I may venture an opinion, sir, I think Master Dick may have put his finger on it.

- Blindfold?

- Uh, no, sir. Grammar. The sentence was grammatically incorrect.

- One does not laugh good, sir. One laughs well.

- Why, that's it. Laughs well. Laughwell. Professor James J. Laughwell.

- Holy safari! The one that just got back from Africa with a collection of rare masks and objects of art.

- That's where the blindfold part would come in, sir.

[...]