Grammatically, the term functions as a proper noun. It operates as a unique name or specific identifier for a particular subject, concept, or entity. The phrase combines the numerical designator "911," associated with emergency services in North America, and the word "kostel," a noun from Slavic languages (e.g., Czech, Slovak) meaning "church." This combination creates a specific title or label rather than a descriptive phrase.
As a proper noun, the term acts as a single semantic unit. Its function is not to modify another word (as an adjective would) or to express an action (as a verb would). Instead, it names the central topic of discussion. The juxtaposition of a well-known emergency number with a specific foreign word for a religious building suggests the term may be a codename, a symbolic title for a project or event, or a unique name for a specific place or piece of art. The analysis of its part of speech is crucial because it establishes the term as the specific subject matter, rather than a general description.
Therefore, in the context of writing an article, this phrase should be treated as the name of the topic. This dictates its syntactic role within sentences; it can serve as a subject, a direct object, or an object of a preposition. Understanding its function as a proper noun ensures grammatical precision and maintains a clear, consistent focus on the specific entity it represents throughout the text.