The keyword term "911 incident" is a noun phrase. The headword, which establishes the primary part of speech, is "incident," which is a noun. The numerical identifier "911," derived from the proper noun for the September 11th attacks, functions as a noun adjunct or an attributive noun, essentially acting as an adjective to modify and specify which incident is being discussed.
In this grammatical structure, "911" qualifies the noun "incident." This is a common English construction where a noun is used to describe another noun (e.g., "kitchen table," "security system"). The entire two-word phrase operates as a single conceptual unit that refers to a specific event or category of events. As a noun phrase, it can serve as the subject of a sentence (e.g., "The 911 incident altered global politics."), the direct object of a verb, or the object of a preposition.
Determining that the term functions as a noun is crucial because it frames the article's subject as a distinct, definable event. This allows the topic to be treated as a concrete entity that can be analyzed in terms of its causes, components, and effects. This grammatical classification ensures the focus remains on the event itself as a subject of study, rather than on an action (verb) or a quality (adjective), providing a clear and stable foundation for the article's content.
