What is a metaphor?

A metaphor is indeed a figure of speech that implies a comparison between two unlike things without using "like" or "as." This allows for a deeper and often more vivid understanding of an idea, as it conveys meaning beyond the literal interpretation. For example, saying "time is a thief" suggests that time steals moments from our lives, enriching the concept of time with emotional weight and emphasizing its fleeting nature. This implied comparison helps to create a more evocative image in the reader's mind, demonstrating how metaphors enhance language and expression.

The other options do not accurately define a metaphor. A direct comparison using "like" or "as" describes a simile, and a tool for measuring time does not pertain to literary devices or comparisons at all. A narrative element of storytelling refers to components such as plot or character development, which are distinct from figurative language like metaphors.