quahog

(noun) Atlantic coast round clams with hard shells; large clams usually used for chowders or other clam dishes. Synonyms: quahaug, hard-shell clam, round clam.

(noun) an edible American clam; the heavy shells were used as money by some American Indians. Synonyms: quahaug, hard-shell clam, hard clam, round clam, Venus mercenaria, Mercenaria mercenaria.