any of various aquatic and land reptiles having a bony shell and flipper-like limbs for swimming | the hard largely calcareous covering of a mollusc or a brachiopod |
a sweater or jersey with a high close-fitting collar | hard outer covering or case of certain organisms such as arthropods and turtles |
| ammunition consisting of a cylindrical metal casing containing an explosive charge and a projectile; fired from a large gun |
| a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners) |
| 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 |