Understatement (noun)

A statement that represents something as less important or serious than it actually is.

Origin:

Under + statement.

Examples:

1. Saying that it was "a little bit chilly" outside when it was clearly freezing, would be an understatement.
2. When he said that he was "slightly annoyed" with the delay, it was an understatement. He was furious.
3. It would be an understatement to say that the weather was bad, it was a complete disaster.
4. It was an understatement to say that the company was "struggling", it was on the verge of bankruptcy.
5. His description of the food as "not bad" was an understatement. It was delicious.