Which word describes language that expresses a contrasting or ironic effect?

The word that describes language expressing a contrasting or ironic effect is "understatement." Understatement refers to the deliberate presentation of something as less significant or smaller than it actually is, often creating a contrast with reality. This contrast can lead to ironic or humorous effects, as it invites the reader to recognize the gap between the statement and the actual situation.

For example, if someone won a major award and remarked, "Oh, it’s just a little trophy," that would be an understatement that contrasts the reality of the award's significance. The language subtly implies more than what is stated, thus creating an ironic effect.

Other terms like exaggeration, metaphor, and allusion have different functions in language. Exaggeration amplifies or magnifies a situation, metaphor draws comparisons between different concepts, and allusion references a well-known event or figure. None of these terms aligns as closely with the idea of highlighting contrast or irony as understatement does.