| pupa |
an insect in a middle stage of its development, after it is a larva. Pupas do not eat or move; they are changing into their adult form. Many kinds of insects, including butterflies, spend their time as a pupa inside a cocoon. |
| ramrod |
a rod that fits inside the barrel of a gun. A ramrod is used for pushing gunpowder into the barrel or for cleaning the barrel of the gun. |
| reptile |
a cold-blooded animal with a skeleton inside its body and dry scales or hard plates on its skin. Most reptiles lay eggs with soft, leathery shells. Some kinds of reptiles live in water, but use their noses to breathe air into their lungs. Lizards, turtles, snakes, and crocodiles are kinds of reptiles. Most reptiles have short legs, but snakes creep on the ground without legs. |
| retina |
the part of the eye at the back of the inside of the eyeball. The retina has cells that sense light and color. Images are formed on the retina and sent to the brain. |
| reverse |
to turn inside out or over. [1/9 definitions] |
| roundhouse |
a round building with a turntable inside where trains are repaired and stored. |
| scallop |
a small invertebrate animal that lives in the ocean. A scallop lives inside of two shells that are attached to each other with a kind of hinge. These rounded, ribbed shells protect the scallop's soft body. The hinged shells can be opened and closed using a large muscle of the scallop. People sometimes eat this muscle. Scallops are mollusks and are closely related to clams and mussels. [1/4 definitions] |
| sea urchin |
a small sea animal with a soft body inside a hard, round shell. Its shell is covered with long, thin spines. Sea urchins are related to starfish. |
| shutter |
a wooden or metal cover that closes over the outside or inside of a window. [1/2 definitions] |
| snowboarding |
the activity or sport of riding a snowboard down a hill over snow or inside specially designed tubes. |
| spinal cord |
the thick cord of nerve tissue inside the spine that runs from the base of the brain to the end of the spine. |
| starboard |
the right side of a ship or aircraft when facing forward from inside. [1/2 definitions] |
| stethoscope |
an instrument that makes the sounds inside a body louder. Doctors and nurses listen to the heart with a stethoscope. |
| throat |
the narrow passage inside the neck. Food and air pass through the throat to the stomach and lungs. [1/2 definitions] |
| vacuum |
a space or container from which most of the air has been removed. Outer space and the inside of a light bulb are examples of vacuums. [1/4 definitions] |
| vertebrate |
an animal that has a skeleton with a backbone inside its body. Mammals, birds, amphibians, reptiles, and fish are large groups of vertebrates. [1/2 definitions] |
| visor |
a flap above the inside windshield of a vehicle that shields the eyes from glare. [1/3 definitions] |
| wastebasket |
an open container for holding trash. A wastebasket is used inside a home or other building. |
| water moccasin |
a venomous snake found in swamps or wet areas of the southern United States. The water moccasin is brown or olive in color and shows the white inside of its mouth when threatened. |
| within |
in the inner part of; inside. [1/3 definitions] |
| woodwork |
door and window frames and other wooden parts inside a house, or other objects or parts made of wood. |