It would be an understatement to say that

- It would be an understatement to say that ...(Madrid is noisy)
descripción insuficiente; decir que.... sería quedarse corto...
- To say it wasn't well attended is an understatement
(decir que estaba poco concurrido es quedarse corto)
- It would be an understatement to say that the Akkadians and the Sumerians did not get along.
- To say that the interrogations were brutal would be an understatement.
- It would be an understatement to say there is a weight problem in America.Understatement is used when a speaker wants to a make a situation seem less strong or important than it is.
Use:
1)For example, think about this situation:
You have taken ten exams in school and passed them all with a score of 100%. Someone asks you: 'How did you do on your test?' You answer: 'I did OK.'

This is understatement. We can also call this modesty.

It would not be understatement to say: 'I did fantastic! I had the best result! I’m wonderful!' We would call this a boast.
2)Being polite using understatement.
In spoken English we use understatement when we want to be tactful.
For example(Bob is really fat but…) How would you describe him? It’s not polite to call him 'fat'.Here we can use 'understatement' to be polite. Take a look at these set of expressions. All of these are ways we would use understatement to describe Bob.

• He's not the thinnest person in the world.
• He's a little on the big side.
• I wouldn’t say he was thin.
  Key-words
  Modesty (noun): when someone does not talk about their good abilities and achievements. Positive meaning.
  Boast (Verb/noun): when someone talks too proudly about their abilities or achievements. Negative meaning.
  Tactful (adjective): careful not to say or do anything that could upset someone.