The keyword term "september 11 bank holiday" functions as a noun phrase. In this construction, "holiday" is the head noun, which is the core subject. The other words act as modifiers that specify the type and date of this holiday.
A detailed grammatical breakdown reveals that "bank" is an attributive noun, functioning as an adjective to describe the kind of holiday (one observed by financial institutions). "September 11" is a proper noun phrase that also acts as an adjectival modifier, specifying the exact date of the holiday. The entire phrase, therefore, names a specific, singular concept: a bank holiday occurring on September 11.
Understanding this grammatical role is critical because it dictates that an article using this keyword must treat the concept as a subject or an object. The article's main point will be to define, describe, or discuss the existence or proposal of this specific holiday itself, rather than treating the words as separate actions or descriptions. The focus is on the thing named by the noun phrase.
