litotes

noun

Etymology: Learned borrowing from Late Latin lītotēs, from Ancient Greek λιτότης (litótēs, literally “plainness”), from λιτός (litós, “simple”).

1. A figure of speech whereby something is stated by denying its opposite.

   “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.”

2. A figure of speech whereby something is stated by denying its opposite.