The keyword term is a noun phrase. In this construction, the word "tribute" serves as the head noun, which is the central grammatical element. The preceding words, "Patriot Day," function as a compound noun adjunct, a type of modifier that specifies the nature of the tribute. The entire phrase collectively names a specific concept or event.
A grammatical analysis reveals "tribute" as the core noun, signifying an act of homage or remembrance. The term "Patriot Day" is itself a compound noun (specifically, a proper noun), where "Patriot" modifies "Day" to name a specific observance. When combined, this compound noun acts as an adjectival modifier for the head noun ("tribute"). This structure is common in English, where one noun modifies another to create a more specific meaning, answering the question "What kind of tribute?".
Recognizing the term as a noun phrase is critical for the article's focus. It establishes the subject as a tangible concept or a class of events to be defined, described, and analyzed. Therefore, the article's main point will be to explain this specific type of homage, detailing its various forms (e.g., ceremonies, memorials, moments of silence) and exploring its cultural and historical significance, rather than framing it as an action (verb) or a complete thought (clause).