The grammatical function of the term is a noun phrase. In this construction, the word "scene" serves as the head noun, which is the central element of the phrase. The preceding words "Patriots Day," "movie," and "shootout"all function as adjectival modifiers that specify and describe the head noun.
A detailed analysis reveals a hierarchy of modification. "Scene" is the core concept. The noun "shootout" acts as an attributive noun (or noun adjunct), specifying the type of scene. This compound, "shootout scene," is then modified by the attributive noun "movie." Finally, the proper noun "Patriots Day" functions as an adjectival modifier to specify which movie is being referenced. This stacking of nouns to modify a final head noun is a common grammatical structure in English used to create highly specific and descriptive terms.
Recognizing this structure as a noun phrase is critical for its correct usage within an article. It dictates that the phrase can function as a subject (e.g., "The patriots day movie shootout scene is intense."), an object (e.g., "The director analyzed the patriots day movie shootout scene."), or the object of a preposition (e.g., "The article focuses on the patriots day movie shootout scene."). This grammatical understanding ensures syntactic accuracy and clarity in writing, preventing the phrase from being mistaken for a clause or other sentence component.