1. the hard shells of clams, typically consisting of two hinged parts
2. containers or packaging that open and close like a clamshell, with two hinged parts

Examples

• The children collected colorful clamshells along the beach.
• She used the empty clamshells as small bowls for her art project.
• The takeout food came in plastic clamshells that could be recycled.
• Ancient clamshells were found in the archaeological dig site.
• The jewelry was displayed in clear plastic clamshells at the store.
• We found several large clamshells washed up after the storm.