The keyword term functions as a compound proper noun phrase. This classification is based on its role as a specific identifier for a unique entity: a particular civic holiday observed within a distinct geographical context. The components collectively name a specific event rather than describing a quality, expressing an action, or modifying another word.
A grammatical analysis of the phrase reveals its composite nature. "Patriot's Day" is the primary proper noun, naming the holiday. "Boston" and "MA" (Massachusetts) are also proper nouns that act as locative modifiers, specifying the location of the observance. In digital contexts like search queries or data tagging, such concatenated terms form a single semantic unit that functions as a noun, pointing to a precise subject. The entire phrase operates cohesively to designate a singular, well-defined topic: the observance of this holiday in this city and state.
The practical application of identifying this term as a proper noun phrase is that it establishes the article's core subject as a specific thing, event, or concept. Consequently, the article's content should focus on defining and describing this event. The main point is not an action (verb) or a characteristic (adjective), but the event itself. This directs the narrative structure toward encyclopedic or descriptive content, such as its history, associated traditions (e.g., the Boston Marathon), and cultural significance within the specified region.
