Clamshells

noun

1. The shell of a clam.
2. A dredging bucket with hinges like the shell of a clam.
3. In food service, the closing box (usually styrofoam but sometimes cardboard) given to consumers with take-out food.
4. Any object that has a hinge on one edge and two surfaces that close together.
5. An amphitheater, especially an outdoor amphitheater; the semi-circular acoustic backdrop behind and above the performers.