a.

1. 有苦味的，苦的
   The defeat was a bitter pill to swallow.

   战败是不得不接受的屈辱（苦处）。

   The medicine tastes bitter.

   此药味苦。

2. 痛苦的；难堪的
   They learned a bitter lesson.

   他们接受了惨痛的教训。

3. 极冷的，严寒刺骨的
   The wind is bitter.

   寒风刺骨。

4. 充满仇恨的；极为不满的
5. 激烈的；尖刻的
   Why was he so bitter against me?

   他为何对我如此刻薄？

ad.

1. 严寒刺骨地
2. 激烈地

n.

1. 苦味；辛酸[C]
2. 【英】苦啤酒[U]

adj.

1. having a sharp, pungent taste or smell; not sweet.
2. causing pain or unhappiness.
   ▸feeling or showing angry hurt or resentment.
   ▸(of a conflict) harsh and acrimonious.
3. (of wind or weather) intensely cold.

n.

1. Brit. beer that is strongly flavoured with hops and has a bitter taste.
2. (bitters) [treated as sing.] alcohol flavoured with bitter plant extracts, used as an additive in cocktails.