understatement
US /ˌʌn.dɚˈsteɪt.mənt/
UK /ˌʌn.dɚˈsteɪt.mənt/

1.
Untertreibung
the presentation of something as being smaller, worse, or less important than it actually is
:
•
To say it was difficult would be an understatement.
Zu sagen, es sei schwierig gewesen, wäre eine Untertreibung.
•
His calm reaction was a huge understatement of his true feelings.
Seine ruhige Reaktion war eine große Untertreibung seiner wahren Gefühle.