The keyword term "patriots day cast" functions as a noun phrase. The main point and core part of speech is the head noun, "cast."
In this construction, "cast" is a noun that refers to the collective group of actors in a performance. The term "Patriots Day," which is a proper noun (the title of the film), acts as a noun adjunct. A noun adjunct is a noun that modifies another noun, functioning like an adjective. Its purpose is to specify which particular cast is being discussed. Therefore, "Patriots Day" modifies "cast" to create a more specific and singular concept: the group of actors associated with the film Patriots Day.
For the purpose of an article, identifying "cast" as the head noun is crucial. It establishes that the subject matter is not the event of Patriots' Day itself, nor the film in its entirety, but specifically the ensemble of actors who performed in it. The article's content should focus on who the actors are, the characters they portrayed, and details related to their performances in that specific production.
