Understatement Definition. Understatement is a form of speech in which a lesser expression is used 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. Understatement is a staple of humor in English-speaking cultures, especially in British humour. For example, in Monty Python's The Meaning of Life, a suburban dinner party is invaded by Death, who wears a long black cloak and carries a scythe.