Crushing grief or sorrow.
Crushing grief or sorrow — most often from lost love, but also from any deep personal disappointment.
Intense, crushing grief tied to a specific painful cause — most prototypically lost or unrequited love, but extending to any shattering letdown. More cause-specific and intimate than the diffuse misery or woe, and more acute than sadness, gloom, or dejection. Unlike grief and mourning (centered on death), heartbreak's central image is romantic loss or betrayal. Overlaps with anguish in intensity but carries the specific “broken heart” metaphor. Far more shattering than mere disappointment.
1570s, from heart + break, “overwhelming grief or sorrow.” The expression “break (someone's) heart” is older, from c. 1400. Heart (Old English heorte) already carried the figurative sense of the seat of love and affection.
The compound has meant “overwhelming grief” since the 1570s, building on the figurative heart and the c. 1400 idiom “break someone's heart.” The strong modern association with romantic loss is consistent with this but not separately dated in the sources. No reliable recent-generation shift.