°A
bivalve mollusk of many kinds, especially those that are edible; as, the long clam (
Mya arenaria), the
quahog or round clam (
Venus mercenaria), the
sea clam or
hen clam (
Spisula solidissima), and other species of the United States. The name is said to have been given originally to the
Tridacna gigas, a huge East Indian bivalve.