litotes (n.)youdaoicibaDictYouDict[litotes 词源字典]
rhetorical figure in which an affirmative is expressed by the negative of its opposite, from Greek litotes, literally "plainness, simplicity," from litos "smooth, plain, small, meager," from PIE root *(s)lei- "slimy, sticky, slippery" (hence "smooth"); see slime (n.).[litotes etymology, litotes origin, 英语词源]