dolour vs heartbreak

dolour and heartbreak both are nouns.

Word	Noun	Adjective	Verb	Adverb
dolour	Yes	No	No	No
heartbreak	Yes	No	No	No

As nouns, heartbreak is a hypernym of dolour; that is, heartbreak is a word with a broader meaning than dolour:

dolour: (poetry) painful grief
heartbreak: intense sorrow caused by loss of a loved one (especially by death)

Other hypernyms of dolour include brokenheartedness, grief, heartache.

dolour (noun)	heartbreak (noun)
(poetry) painful grief	intense sorrow caused by loss of a loved one (especially by death)