Noun | 1. | ![]() clam - burrowing marine mollusk living on sand or mud; the shell closes with viselike firmness genus Venus, Venus - type genus of the family Veneridae: genus of edible clams with thick oval shells littleneck, littleneck clam - a young quahog cherrystone, cherrystone clam - a half-grown quahog hard-shell clam, quahaug, quahog, round clam - Atlantic coast round clams with hard shells; large clams usually used for chowders or other clam dishes |