one of the paired hinged shells of certain molluscs and of brachiopods | the hard largely calcareous covering of a mollusc or a brachiopod |
the entire one-piece shell of a snail and certain other molluscs | hard outer covering or case of certain organisms such as arthropods and turtles |
control consisting of a mechanical device for controlling the flow of a fluid | ammunition consisting of a cylindrical metal casing containing an explosive charge and a projectile; fired from a large gun |
device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone | a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners) |
a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it | the housing or outer covering of something |
| a very light narrow racing boat |
| a rigid covering that envelops an object |
| the exterior covering of a bird's egg |
| the hard usually fibrous outer layer of some fruits especially nuts |
| the material that forms the hard outer covering of many animals |