1. expressing with restraint or lack of emphasis, usually used for an
[ironic' or rhetorical effect.
2.basically a figure of speech that writers use to subtly
make a situation less important or
serious than it really is.
Saying "We've had a little rain," when the neighborhood is flooded.
Now that is an understatement.
The last
line of
Frost's "Birches" illustrates understatement: "One could do worse than be a swinger of birches."