heartrending

Dolorous is a related term of heartrending.

As adjectives the difference between dolorous and heartrending

is that dolorous is solemnly or ponderously sad while heartrending is that causes great grief, anguish or distress.

As a noun taxonomy

is the science or the technique used to make a classification.

As an adjective heartrending is

that causes great grief, anguish or distress.

As adjectives the difference between heartrending and melancholy

is that heartrending is that causes great grief, anguish or distress while melancholy is affected with great sadness or depression.

As a noun melancholy is

(historical) black bile, formerly thought to be one of the four "cardinal humours" of animal bodies.