The keyword phrase "patriots day boston" functions as a proper noun phrase. Within this structure, the core component is the proper noun "Patriots Day," which is the name of a specific holiday. The entire phrase operates as a single unit to name a particular event or concept.
Grammatically, the term "Boston," itself a proper noun, acts as a noun adjunct (or attributive noun). A noun adjunct is a noun that modifies another noun, functioning similarly to an adjective. In this case, "Boston" specifies the location and context of "Patriots Day," distinguishing it from observances of the holiday in other locations, such as Maine. It answers the question "Which Patriots Day?" The head noun, or the central word being modified, is "Day."
Understanding this phrase as a proper noun is critical because it defines the subject as a singular, specific entity. For content creation, this means the article's focus is on a particular event (the Boston observance of the holiday), not a general description of a day for patriots. The phrase would be used in a sentence as a subject or object, such as, "Patriots Day Boston draws thousands of visitors," where the entire phrase acts as the sentence's subject.
