n The shell of a clam.
n Any object that, in (literal or figurative) resemblance to the shell of a clam, has a hinge on one edge and two surfaces that close together.
n A dredging bucket with hinges like the shell of a clam.
n In food service, the closing box (usually styrofoam but sometimes cardboard) given to consumers with take-out food.
n (obsolete, US, slang) mouth
n (often attributive) Any object with some other resemblance to either one or both halves of the shell of a clam.
n (music) An amphitheater, especially an outdoor amphitheater; the semi-circular acoustic backdrop behind and above the performers.
v (manufacturing) To deform a die in a shape resembling the shell of a clam, as a result of uneven extrusion pressure.
v To dig out by means of a clamshell (dredging bucket).
v To compress or flatten underwater debris so as to avoid blocking a channel.
v (transitive, intransitive) To open or close by means of a hinge, similar to the way a clamshell opens and closes.