Unicorn.

An imaginary animal that looks like a horse and has a straight horn growing from the middle of its forehead.

Universe.

All of space and everything in it including stars, planets, galaxies, etc.

Unicycle.

A vehicle that is similar to a bicycle but has only one wheel —compare bicycle, tricycle.

Utensil.

A simple and useful device that is used for doing tasks in a person's home and especially in the kitchen.

Van.

A vehicle that is used for transporting goods and that is closed in on all sides.

Violin.

A musical instrument that has four strings and that you usually hold against your shoulder under your chin and play with a bow.

Volcano.

Mountain with a hole in the top or side that sometimes sends out rocks, ash, lava, etc., in a sudden explosion (called an eruption).

Vulture.

Any one of several large birds that eat dead animals and have a small and featherless head.

Walrus.

A large animal that lives on land and in the sea in northern regions and that has flippers and long tusks.

Watermelon.

A large, round fruit that has hard, green skin, sweet, red, juicy flesh, and black seeds.

Wolf.

A large wild animal that is similar to a dog and that often hunts in groups.

Woodpecker.

A bird that has a very hard beak which it uses to make holes in trees to get insects for food.

X-ray.

To examine and make images of (things, such as the bones and organs inside the body) by using X-rays.

Xylophone.

A musical instrument that has a set of wooden bars of different lengths that are hit with hammers.

Ox.

A bull that has had its sex organs removed.

Fox.

A small wild animal that is related to dogs and that has a long pointed nose and a bushy tail.

Yacht.

A large boat that is used for racing or pleasure.

Yak.

A large wild animal that has long hair and curved horns and that lives in central Asia.

Yarn.

A long, thin piece of cotton, wool, etc., that is thicker than thread and that is used for knitting and weaving.

Yoyo.

A round toy that has two flat sides with a string attached to its center, that is held in your hand, and that is made to go up and down by unwinding and rewinding the string with a movement of your wrist.

Zebra.

An African animal that looks like a horse and has black and white stripes covering its body.

Zigzag.

A line that has a series of short, sharp turns or angles.

Zipper.

A device that is made of two rows of metal or plastic teeth and another piece that slides over the teeth to make them fit together or come apart and that is used to fasten clothing, open or close bags, etc.

Zoo.

A place where many kinds of animals are kept so that people can see them.