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Any of numerous freshwater and marine mollusks of the class Bivalvia, having a shell consisting of two hinged valves connected by a ligament, and including the clams, mussels, oysters, and scallops. Also called lamellibranch, pelecypod.
1. Having a shell consisting of two hinged valves.
2. Consisting of two similar separable parts.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.