The primary part of speech for the main point of the keyword phrase "patriot day definition for kids" is a noun. The core word that establishes the subject is "definition."
While the entire phrase functions as a noun phrase, the head noun is "definition." The words "Patriot Day" act as an adjectival noun, modifying "definition" to specify its subject matter. The prepositional phrase "for kids" further modifies the noun by specifying the target audience. Therefore, the central grammatical and conceptual element is the noun "definition."
This determination is crucial because it establishes that the article's primary function is to be informational and explanatory. The content must focus on providing a clear and accessible explanation (a definition) of a specific topic (Patriot Day) for a particular demographic (kids), rather than persuading, narrating a story, or instructing on a process.