#understatement  a statement that is restrained in ironic contrast to what might have been said
  exclusion:  overstatement
  supertype:  statement  a message that is stated or declared; a communication (oral or written) setting forth particulars or facts etc; "according to his statement he was in London on that day"
  subtype:  litotes__litote__meiosis  understatement for rhetorical effect (especially when expressing an affirmative by negating its contrary); "saying `I was not a little upset' when you mean `I was very upset' is an example of litotes"

No statement uses or specializes understatement; click here to add one.