bleeding heart

Short definition from Wiktionary

Noun

1. 1
   Any of various perennial plants, of the family Papaveraceae, subfamily Fumarioideae, often having pink heart-shaped flowers, including: Lamprocapnos spectabilis (formerly Dicentra spectabilis), a popular garden plant with arching sprays of pendent red and white (or pure white) flowers.
2. 2
   Any of various perennial plants, of the family Papaveraceae, subfamily Fumarioideae, often having pink heart-shaped flowers, including: Dicentra, a genus native to eastern Asia and North America, some species with colors and shape similar to Lamprocapnos spectabilis.
3. 3
   Any of various perennial plants, of the family Papaveraceae, subfamily Fumarioideae, often having pink heart-shaped flowers, including: Ehrendorferia, a genus native to California, usually with yellow flowers of similar shape.
4. 4
   Any of various perennial plants, of the family Papaveraceae, subfamily Fumarioideae, often having pink heart-shaped flowers, including: Dactylicapnos, a genus native to Himalayas and mountainous areas of South China, Burma and Vietnam, usually with yellow flowers of similar shape.
5. 5
   Flowering shrubs, lianas, or small trees of the mint family Lamiaceae, in the genus Clerodendrum.
6. 6
   The bleeding heart tree, Homalanthus populifolius, an Australian rainforest plant.
7. 7
   A person who is overly sympathetic to the plight of the underprivileged, exploited or helpless, or to casualties of circumstance.
8. 8
   Any of several species of bird in the genus Gallicolumba of the pigeon family, native to the Philippines, characterised by a red patch on the plumage of the breast.
9. 9
   A person who is overly sympathetic to the plight of the underprivileged or exploited.

Adjective

1. 1
   Overly sympathetic to the plight of the underprivileged or exploited.