What is the term for a comparison that is developed throughout an entire literary work?

The term for a comparison that is developed throughout an entire literary work is an extended metaphor. This literary device involves taking a metaphor—a figure of speech that describes one thing in terms of another—and elaborating on that comparison over several lines, paragraphs, or even throughout the entire work. By doing so, the author can create deeper layers of meaning and connect ideas in a more comprehensive way.

An extended metaphor may enhance readers’ understanding of complex themes or characterize elements in a uniform manner, leading to a cohesive reading experience. The sustained nature of this comparison allows the author to explore different facets of the metaphor as the narrative progresses, making it a powerful tool for thematic development and reader engagement.

In contrast, an analogy typically draws a comparison between two different things for the purpose of explanation, often utilizing one instance to clarify another, but not developing that comparison as extensively as an extended metaphor does. Hyperbole involves exaggerated statements not meant to be taken literally, while a simile makes a comparison using "like" or "as" but is generally limited to a brief expression rather than a protracted exploration. Thus, the unique nature and structure of an extended metaphor set it apart as the correct answer.