Understatement is a figure of speech where a writer or speaker deliberately makes a situation seem less important or serious than it actually is. This can be done for humorous effect, to create irony, or to emphasize the true significance of something by contrasting it with a downplayed description.
For example:
* "I've got a slight headache." (When the person is actually experiencing a debilitating migraine)
* "It's a bit chilly outside." (When it's actually freezing cold)
In a humorous story, understatement can be used to create a comedic effect by playing with the reader's expectations. The reader might be expecting a dramatic or significant event, but the author downplays it, leading to an amusing contrast.