n.
1.
Bitter taste, acridity, acridness.
2.
Intensity, poignancy, grievousness, severity.
3.
Spleen, gall, rankling, rancor, heart-burning, animosity, hatred, malice, malignity, spite, enmity, ill-will, bad blood.
4.
Asperity, acerbity, severity, harshness, acrimony, ill-temper.
5.
Distress, pain, grief, sorrow, affliction, heaviness, regret, despondency.