Understatement is a form of speech or disclosure which contains an expression of lesser strength than would be expected. Understatement may be employed for emphasis, for humour, or ironically. This is not to be confused with euphemism, where a polite phrase is used in place of a harsher or more offensive expression, though understatement too can be used to moderate something that might seem harsh.
The figure of speech used in understatement, litotes, is always deliberate.
Understatement is often associated with traditional English culture, where it may be used for comic effect, or may refer to the verbally calm English way of dealing with extreme situations.