Litotes

An understated or ironic figure of speech in which an idea or thing is emphasised by rejecting its opposite, for example ‘You won’t be sorry’ to convey satisfaction or pleasure.

A more extensive list of literary terms, with quotations from fiction and non-fiction sources showing the terms in use, is included in The Right Word: A Writer’s Toolkit of Grammar, Vocabulary and Literary Terms (Bloomsbury 2021) 

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