The book Jerome was carrying a dictionary fell into the mud. appositive?

The appositive phrase in the sentence is "a dictionary".

Here's why:

* Appositives are words or phrases that rename or explain a noun or pronoun that comes before them.

* In this sentence, "a dictionary" renames the noun "book."

* The phrase is set off by commas, which is a common way to indicate an appositive.

Let me know if you'd like to see more examples of appositives!