from the GNU version of the Collaborative International Dictionary of English
- n. Any one of numerous species of small marine bivalves belonging to Donax and allied genera in which the shell is wedge-shaped.
from The Century Dictionary and Cyclopedia
- n. A bivalve mollusk of the family Donacidæ.
Sorry, no etymologies found.
There are several varieties of these archaic relics, some flat, others lenticular or of a wedge-shell shape, and others, still, concave on one side and convex on the other.