Noun: heart urchin haa(r)t ur-chin
- Sea urchin having a heart-shaped body in a rigid spiny shell
"The heart urchin burrowed into the soft sediment of the seafloor"
Derived forms: heart urchins
Type of: sea urchin, urchin
Part of: order Spatangoida, Spatangoida
Encyclopedia: Heart urchin