What is the role of an appositive in a sentence?

An appositive serves the role of clarifying or defining an unfamiliar word by providing additional information about a noun. It typically follows the noun it describes, offering a more detailed or specific identification. For example, in the sentence "My brother, an avid cyclist, rides every weekend," the appositive "an avid cyclist" clarifies who “my brother” is, giving the reader more context about his interests. This addition enhances the reader's understanding, especially if the noun by itself may not convey complete information. The function of an appositive is crucial in enriching the text and ensuring clarity in communication.