The keyword term is a compound noun. Its grammatical core, or head noun, is "festival." The preceding words, "patriot day," function together as a compound modifier that specifies the nature or occasion of the festival.
In this construction, "festival" is the primary noun that identifies the subject as an event or celebration. The words "patriot" and "day" act as noun adjuncts or attributive nouns. "Patriot" modifies "day" to specify the type of day, and the resulting two-word unit, "patriot day," modifies "festival." This hierarchical modification serves to classify the event, distinguishing it from other types such as a "music festival" or "film festival."
Identifying "festival" as the head noun is crucial for correct syntax and semantic focus. In any sentence, the verb must agree with this singular noun (e.g., "The festival is..."), and any related pronouns should refer to it (e.g., " It was well-attended"). This grammatical analysis establishes the event itself as the central topic, while its theme is the defining attribute.
