Hyperbole is the use of exaggeration

Exaggeration

Exaggeration is a representation of something in an excessive manner. The exaggerator has been a familiar figure in Western culture since at least Aristotle's discussion of the alazon: 'the boaster is regarded as one who pretends to have distinguished qualities which he possesses either not at all...

 as a rhetorical device

Rhetorical device

In rhetoric, a rhetorical device or resource of language is a technique that an author or speaker uses to convey to the listener or reader a meaning with the goal of persuading him or her towards considering a topic from a different perspective. While rhetorical devices may be used to evoke an...

 or figure of speech

Figure of speech

A figure of speech is the use of a word or words diverging from its usual meaning. It can also be a special repetition, arrangement or omission of words with literal meaning, or a phrase with a specialized meaning not based on the literal meaning of the words in it, as in idiom, metaphor, simile,...

. It may be used to evoke strong feelings or to create a strong impression, but is not meant to be taken literally.

Hyperboles are exaggerations to create emphasis or effect. As a literary device, hyperbole is often used in poetry

Poetry

Poetry is a form of literary art in which language is used for its aesthetic and evocative qualities in addition to, or in lieu of, its apparent meaning...

, and is frequently encountered in casual speech. An example of hyperbole is: "The bag weighed a ton." Hyperbole helps to make the point that the bag was very heavy, although it is not probable that it would actually weigh a ton.

In rhetoric

Rhetoric

Rhetoric is the art of discourse, an art that aims to improve the facility of speakers or writers who attempt to inform, persuade, or motivate particular audiences in specific situations. As a subject of formal study and a productive civic practice, rhetoric has played a central role in the Western...

, some opposites of hyperbole are meiosis

Meiosis (figure of speech)

In rhetoric, meiosis is a euphemistic figure of speech that intentionally understates something or implies that it is lesser in significance or size than it really is. Meiosis is the opposite of auxesis, and also sometimes used as a synonym for litotes...

, litotes

Litotes

In rhetoric, litotes is a figure of speech in which understatement is employed for rhetorical effect when an idea is expressed by a denial of its opposite, principally via double negatives....

, understatement

Understatement

Understatement is a form of speech which contains an expression of less strength than what would be expected. This is not to be confused with euphemism, where a polite phrase is used in place of a harsher or more offensive expression....

, and bathos

Bathos

Bathos is an abrupt transition in style from the exalted to the commonplace, producing a ludicrous effect. While often unintended, bathos may be used deliberately to produce a humorous effect. If bathos is overt, it may be described as Burlesque or mock-heroic...

(the 'letdown' after a hyperbole in a phrase).