Litotes

lie-TOE-tees

 This offspring of understatement denies an exaggeration. The word comes from the Greek, litos, meaning “plain” or “meager.” (Hardly an over-the-top name, what?) You might call it an ironic form of hyperbole; by denying an exaggeration, the litotes tends to make an exaggeration of its own. An overstated understatement, if you will. 

The report of my death was an exaggeration. Mark Twain

He didn’t exactly set the art world on fire. Word Hero

I’m not defusing bombs for my health, here. Word Hero