Which figurative expression requires the use of a distancing word like 'like' or 'as'?

The correct answer is simile, which is a figurative expression that explicitly compares two different things using the words "like" or "as." This structure allows for a clear and direct comparison, making it easier for the reader to understand the relationship being drawn between the two subjects. For instance, saying "Her smile was like the sun" illustrates how the smile can be light and warm, engaging the reader's imagination in a particular way.

In contrast, metonymy, metaphor, and synecdoche do not rely on such distancing words. Metonymy involves substituting the name of one thing with the name of something closely related, while metaphor creates an implicit comparison without using "like" or "as," suggesting that one thing is another. Synecdoche, on the other hand, uses a part to represent the whole or vice versa. Each of these figurative expressions conveys ideas and concepts but does so without the explicit comparative structure found in similes.