* bitter 1
a. 苦的，有苦味的
Black coffee leaves a bitter taste in the mouth.
不加奶的咖啡在嘴里留下了一些苦味。
* bitter 2
a. 引起悲伤的；令人难受的
learn from bitter experience
从惨痛教训中吸取教益
Failing the exam was a bitter disappointment to him.
他考试不及格很伤心失望。

* bitterness
n. 苦味；痛苦
Bitterness and resentment only hurt one person, and it's not the person we're resenting--It's us.
* vanilla
n. 香草
* vagina
n. 阴道