| an |
another word for a. It is used before words that start with a, e, i, o, or u, or before words that begin with vowel sounds. |
| analysis |
the process of separating something into parts in order to study it. [1/2 definitions] |
| apostrophe1 |
a punctuation mark ('). It is used to show where one or more letters or numbers have been left out. "Wouldn't" for "would not" and "'87" for "1987" use apostrophes this way. [1/3 definitions] |
| Aral Sea |
formerly, a very large, single lake in Central Asia. Once one of the world's largest lakes, the Aral Sea has lost a great deal of its water in recent times and it has divided into separate parts. The southeastern part of the Aral Sea has become entirely dry and is called a desert now. |
| archaeological |
of or relating to archaeology. Archaeology is the study of human life as it existed a very long time ago. |
| are1 |
a form of the verb "be" that is present tense and used with the pronouns "you," "we," or "they." It is also used with plural nouns. |
| arsenic |
a poisonous substance that is one of the chemical elements. It can be either grayish white, yellow, or black. (symbol: As) |
| ash2 |
a tree that is related to the olive tree. It has seeds that look like wings and leaves of more than one part. [1/2 definitions] |
| Asia |
the largest continent. Asia is surrounded by the Pacific, Indian, and Arctic Oceans, the Red Sea, and eastern Europe. It is in the Eastern Hemisphere. |
| as if |
how it would be if. |
| asphalt |
a sticky black substance like tar. Asphalt is found naturally or obtained when oil is refined. It is used for making roads and roofs and for making things waterproof. [1/2 definitions] |
| assembly line |
a way of putting together a product in a factory by moving it along a line of workers. Each worker adds or adjusts a part until the product is finished. |
| asterisk |
a sign (*). It is used to show that there is other information on the page that explains the information where the sign is placed. |
| asthma |
a disease of the lungs that makes it difficult to breathe. Asthma is often caused by an allergy. |
| Australia |
the smallest continent. Australia is southeast of Asia, between the Indian and Pacific Oceans. It is in the Eastern Hemisphere. [1/2 definitions] |
| automatic |
done without having to think about it. [1/2 definitions] |
| avocado |
a tropical American fruit shaped like a pear. It has a green or black skin and a yellowish green pulp. |
| Aztec |
a member of an Indian people who had an advanced civilization in central Mexico before Spain conquered it in 1519. |
| backhoe |
a machine that is used for digging. It has a large metal bucket that scoops something up and toward the machine. |
| back road |
a road that avoids traffic and high speed travel. It is often a small, country road that goes through areas with few houses and buildings. |
| badger |
a furry mammal with short legs and a long body. The American badger has a white stripe on its forehead that runs down its back, and it has long dark marks on its face also. Badgers eat worms, rodents, rabbits, and plants. Different kinds of badgers live in Europe, Asia, and North America. They are related to skunks, otters, and other kinds of weasels. [1/2 definitions] |