hardworking

bitter melon (bitter gourd, balsam pear, balsam apple, leprosy gourd, bitter cucumber)

pain

exhausting

suffering

difficult

to suffer hardship

vexed

sufferings

bitter water (e.g. mineral water containing sulfates)

poverty-stricken

(old) the family of the victim in a murder case

bitter work

to bear hardships

lit. sea of bitterness

destitute but honest

deprivation

pain and difficulties

painstaking effort

Chinese herbal tea

bitter and astringent

to fight a hard battle; (fig.) to struggle hard

to grumble

depressed