What is a metaphor?

A metaphor is best described as a figure of speech that directly compares one thing to another for rhetorical effect. This definition is accurate because metaphors imply that one thing is another, allowing for a more vivid or imaginative understanding without the use of "like" or "as," which are characteristic of similes.

For instance, if someone says "Time is a thief," they are using a metaphor to suggest that time stealthily takes away moments of our lives, just as a thief would take something valuable. This comparison enhances the reader's understanding by providing a deeper insight into the nature of time.

The other choices relate to different literary devices: the first option describes similes, which are similar but use "like" or "as" for comparison; the third option refers to hyperbole, which involves exaggeration; and the fourth option pertains to characterization, specifically how dialogue reveals traits about characters. Thus, they do not accurately define a metaphor.