litotes
A figure of speech whereby something is stated by denying its opposite.
countable, uncountable
The delicacy which prompts a later generation to reject that name is by no means necessarily a result of stricter habits, is far more often due to the flatness which comes of untiring repetition and to the greater piquancy of litotes.
A figure of speech whereby something is stated by denying its opposite. — The negation of a negative quality to assert a positive.
countable, uncountable
Where it comes from
Learned borrowing from Late Latin lītotēs, from Ancient Greek λιτότης (litótēs, literally “plainness”), from λιτός (litós, “simple”).
Adapted from the Wiktionary entry litotes (CC BY-SA 4.0).