Simile and hyperbole are the terms for two different figures of speech. Simile is the use of words such as “like” to compare an object, concept, or person to something else. Hyperbole is the deliberate use of exaggeration to describe something, as in the sentence, “This suitcase weighs a ton.” Simile and hyperbole can often be confused, because hyperbole sometimes fancifully compares its subject to something else. The key difference is that hyperbole often makes claims that no reasonable person would take literally.
Simile is a kind of metaphor, a common literary device also used often in everyday speech. A metaphor compares something to something else for descriptive or poetic effect. A simile uses words such as “like” or “as” to achieve this, as in the phrase, “She sank like a stone.” There is little exaggeration in this phrase, as it is quite possible for a person to sink like a stone in the right conditions. Other phrases, however, can lead to confusion between simile and metaphor.
The phrase “catlike reflexes,” for example, compares a person’s reflexes to the famously quick response time of felines. This phrase spans the difference between simile and hyperbole; it could be simile, but is more likely hyperbole. Although it is possible for a person to achieve such a high reaction time with training, the average person will not have this kind of training. Describing someone as having “catlike reflexes,” therefore, is most often hyperbole, unless the person in question is a soldier, athlete, or acrobat. In such cases, it could truly be a simile.
In most cases, it is easier to determine the difference between simile and hyperbole. The phrase, “This suitcase weighs a ton,” is clearly hyperbole; no one expects the bag to actually weigh 2,000 pounds. Hyperbole exaggerates the features being described, usually for colorful or persuasive effect. A person may say, “If I ate all that ice cream, I’d be as big as a whale.” Although using the word “as” the way a simile does, the comparison to a gigantic sea mammal reveals the sentence is clearly hyperbole.
The difference between simile and hyperbole, then, comes down to the intended use of the comparison. If the phrase is used to describe something more thoroughly, it is probably a simile, even if it compares two unlike things, as in Robert Burns’ famous line, “My love is like a red red rose.” Burns is discussing his love’s beauty and perfection; he does not expect anyone to mistake her for a flower. If the phrase calls attention to itself for comic or colorful effect, it is probably hyperbole. The sentence, “I need more debt like a hole in the head,” is not intended to describe the debt, just to express its undesirability in a highly exaggerated way.