understatement
n
(a) [U] (action or practice of) understating 有節制的陳述或表達; 少說; 少報
a clever use of understatement, eg for effect 巧妙地輕描淡寫(如為獲得某種效果).
(b) [C] statement that expresses an idea, etc too weakly 重事輕說; 輕描淡寫
To say that he was displeased is an understatement, ie He was furious. 說他不高興是重事輕說(他已怒不可遏).