What is the literary device that uses understatement by negating the opposite of an idea?

The correct answer, litotes, is a figure of speech that employs understatement by expressing an idea through the negation of its opposite. This technique often serves to emphasize a point or convey a sense of modesty by presenting something in a restrained or subdued manner. For instance, saying "not bad" to mean "good" is a common use of litotes. By negating the opposite, it creates a subtle but effective emphasis, making the statement more impactful.

Anaphora refers to the repetition of a word or phrase at the beginning of successive clauses or sentences, creating rhythm or emphasis, but it does not involve understatement. Understatement, while similar in intent, is a broader term that does not specifically involve the negation of opposites. Euphemism, on the other hand, is the use of milder language to replace harsh or direct expressions, serving to soften the impact of a message rather than employing a technique based on negation.