What literary device is defined as a comparison of two unlike things without using "like" or "as"?

The correct answer is metaphor, which is a literary device that directly compares two unlike things by stating that one is the other, rather than using "like" or "as," which would indicate a simile. This type of comparison allows for a deeper understanding of an idea or concept by creating a direct relationship between the objects or ideas being compared. For example, saying "Time is a thief" suggests that time stealthily takes away life's moments, much like a thief would take valuables. This implicit comparison adds richness and depth to the writing, allowing readers to make connections and derive meaning in a more impactful way.

In contrast, a simile uses "like" or "as" to make comparisons, while an analogy is an extended comparison that explains how two different things are alike in certain aspects, and an allusion is a reference to a well-known person, place, event, or work of art. Understanding these distinctions highlights the unique function of metaphors in literature, emphasizing their power in conveying complex ideas succinctly.