bitter和中文的“苦”几乎意思完全一样，如苦寒、苦干、艰苦、辛苦等，除了没有“苦涩”的“涩”。You use bitterly when you are describing an attitude which involves strong, unpleasant emotions such as anger or dislike.
- a bitter pill = an unwanted or unpleasant situation that someone is forced to accept
- sugarcoat a/the bitter pill = make something bad, unpleasant, or dissatisfactory easier to cope with, endure, or accept
- swallow a bitter pill = accept, usually reluctantly, an unwanted or unpleasant situation or truth
- take the bitter with the sweet = accept both the negative and positive aspects of something, typically used in an acknowledgement that nothing is perfect
- the bitter fruit(s) = the negative consequences of something. 苦果和哭过拼音一样，有意思
- the weed of crime bears bitter fruit = illegal, immoral, or illicit schemes will only every yield bad outcomes
- be bitter and twisted = be miserable, typically because of past traumas or problems
- the bitter end = 1. the point of completion or conclusion; 2. the final or most critical extremity, such as death or total defeat
- (fight) to/till/untill the bitter end
