the hard largely calcareous covering of a mollusc or a brachiopod | one of the paired hinged shells of certain molluscs and of brachiopods |
hard outer covering or case of certain organisms such as arthropods and turtles | the entire one-piece shell of a snail and certain other molluscs |
ammunition consisting of a cylindrical metal casing containing an explosive charge and a projectile; fired from a large gun | control consisting of a mechanical device for controlling the flow of a fluid |
a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners) | device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone |
the housing or outer covering of something | a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it |
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 | |