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

1.
eufemismo, subavaliação
the presentation of something as being smaller, worse, or less important than it actually is
:
•
To say it was difficult would be an understatement.
Dizer que foi difícil seria um eufemismo.
•
His calm reaction was a huge understatement of his true feelings.
Sua reação calma foi um grande eufemismo de seus verdadeiros sentimentos.