The term "patriot day documentary" is a noun phrase. Its grammatical function is determined by the head noun, "documentary," which establishes the phrase as representing a specific type of media. The preceding words, "patriot day," act as modifiers that specify the subject of the documentary.
In this structure, "Patriot Day" is a compound proper noun that functions as a noun adjunct, also known as an attributive noun. A noun adjunct is a noun that modifies another noun, effectively performing the role of an adjective. It clarifies the type or category of the head noun. Just as "sports car" specifies a type of car, "patriot day" specifies the subject matter of the "documentary."
This grammatical classification dictates that the main point of an article using this keyword should be to define, describe, analyze, or review this specific category of film. The focus is on the thing itselfa documentary about Patriot Day. The article's content would treat the keyword as its central subject, exploring its themes, production, impact, or specific examples, rather than treating it as an action (verb) or a standalone quality (adjective).
