The keyword term "patriot day parade" is a noun phrase. The main point and the grammatical head of this phrase is the noun "parade". This single word represents the core subject or entity being discussed.
In this construction, "parade" serves as the head noun, which is the central element of the phrase. The preceding words, "Patriot Day," function together as a compound nominal modifier. This modifier acts adjectivally to specify the type or occasion of the parade. "Patriot" modifies "Day," forming the proper noun for the observance, and "Patriot Day" as a unit then modifies "parade," distinguishing it from other types of parades such as a "Thanksgiving Day parade" or a "victory parade."
Understanding that "parade" is the main noun is crucial for article development. It establishes that the primary focus of the content should be the event of the parade itselfits route, participants, themes, and activities. The modifier "Patriot Day" provides the specific context, occasion, and purpose for that event, informing the tone and details of the article, but the central subject remains the procession.