1) Dryness 2) Irony 3) Litotes 1) Statement 
Understatement is a form of speech or disclosure which contains an expression of less strength than what would be expected. This is not to be confused with euphemism, where a polite phrase is used in place of a harsher or more offensive expression. ==British humour== Understatement is a staple of humour in English-speaking cultures. For example, i...
see 'Litotes.'
• (n.) The act of understating, or the condition of being understated; that which is understated; a statement below the truth.
(from the article `rhetoric`) ...(attributing human qualities to a nonhuman being or object), irony (a discrepancy between a speaker`s literal statement and his attitude or ...
A technique of saying less than necessary in a piece of writing (playing down rather than exaggerating) in order to make something clear. The writer or speaker presents some idea as being less important as it really is. Contrast: hyperbole / exaggeration / overstatement
See Litotes.
[n] - a statement that is restrained in ironic contrast to what might have been said
The opposite of hyperbole, understatement (or litotes) refers to a figure of speech that says less than is intended.
A form of irony, also called litotes, in which something is represented as less than it really is, with the intent of drawing attention to and emphasizing the opposite meaning.
Understatement is when a writer presents a situation or thing as if it is less important or serious than it is in reality.
noun a statement that is restrained in ironic contrast to what might have been said
saying that something is smaller or less important than it actually is.
something said in a restrained way for ironic contrast