You use bitterly when you are describing an attitude which involves strong, unpleasant emotions such as anger or dislike.
例句
We are bitterly upset at what has happened.發生的事情讓我們極為心煩。...Lucy Gannon's fine, bitterly funny play.露西·甘農令人捧腹又倍感心酸的優秀劇本
英漢詞典釋義
adv.
苦澀地;痛苦地;不痛快地
He spoke most bitterly of his experiences in prison.他非常痛苦地講述了他在監獄中的經歷。He realized how he had been fooled, and laughed bitterly.他明白了自己是怎么被愚弄的，苦笑起來。
殘酷地;激烈地;非常地
It is bitterly cold today.今天冷得很。A bitterly cold winter damaged industrial output and trade.嚴寒的冬天損害了工業生產和貿易。Regional monopolies were bitterly fought for.為奪取地方壟斷權發生了激烈的競爭。He was ashamed and bitterly humiliated.他感到羞恥,丟盡了面子。