How did merriman expand the meaning of word oratory?

You are likely thinking of Edmund Burke Merriman, a prominent American orator who lived in the 19th century. However, it's not accurate to say that he "expanded the meaning of the word oratory."

Here's why:

* Oratory is a well-established term referring to the art of public speaking, particularly persuasive and eloquent speech. Its meaning was already quite comprehensive before Merriman's time.

* Merriman was known for his skill in oratory, but he didn't introduce new concepts or definitions. He simply excelled in using the existing art of oratory to powerful effect.

Perhaps you are thinking of a specific aspect of Merriman's work that you believe broadened the understanding of oratory? If you could provide more context about what you have in mind, I may be able to give you a more specific answer.