1. A state of deep bitterness and ill will
   "his bitterness took the form of extreme hostility";
   - resentment, gall, rancor [US], rancour [Brit, Cdn], ill feeling, hard feelings, acrimoniousness, bile
    
2. The taste experience when quinine or coffee is taken into the mouth
   "The bitterness of the dark chocolate was balanced by its sweetness";
   - bitter
    
3. The property of having a harsh unpleasant taste
   "The bitterness of the coffee was balanced by a touch of cream";
   - bitter
    
4. A rough and bitter manner
   "The debate descended into bitterness";
   - acrimony, acerbity, jaundice, tartness, thorniness

Type of: disagreeableness, enmity, gustatory perception, gustatory sensation, hostility, ill will, taste, taste perception, taste property, taste sensation

Encyclopedia: Bitterness