| abstract |
When something is abstract, it doesn't have any physical form. Feelings and ideas are abstract things. They are things, but you can't see them or touch them or even smell them! They exist in people's minds only. [1/3 definitions] |
| alien |
a living being from another planet; extraterrestrial. There is no evidence that aliens exist, but many people believe there is life on other planets. [1/5 definitions] |
| ancient |
Something ancient is a thing that existed or happened a very, very long time ago, like an ancient kingdom or an ancient tribe of people. When you read about an "ancient country," that country might still exist now--like Egypt or Greece--but you are reading about that country the way it was maybe thousands of years ago. [1/2 definitions] |
| away |
Sometimes when we say that something goes away, it means that it doesn't exist anymore. It completely disappears. [1/5 definitions] |
| be |
to live or exist. [1/8 definitions] |
| being |
When something has come into being, it means that it has come alive or has begun to exist. [1/2 definitions] |
| biome |
A biome is a type of region on the earth where certain types of plants and animals live naturally because they have adapted to the soil, climate, and other conditions that exist there. Forest and desert are two types of biome. |
| biosphere |
all living organisms together with the environments in which they are able to exist; all earth's ecosystems combined. [1/2 definitions] |
| bring about |
to cause to happen or exist. |
| cease |
If you cease doing something, you stop doing it, or you make something stop or end. If something ceases to exist, it stops living or existing. If something ceases to happen, it stops happening. [1/2 definitions] |
| chemical |
Chemicals are the different substances that exist on the earth and in space. A chemical can be one basic substance, such as oxygen or gold or iron, but we also use the word chemical when we talk about mixtures of things, such as gasoline. People often think of chemicals as liquids, but chemicals can be solids and gases too. Chemicals are things that we can find in nature, but chemicals can also be substances that scientists make for special purposes, such as for medicines or products that we use in our daily lives. [1/2 definitions] |
| chemist |
A chemist is a kind of scientist. A chemist works in the field of chemistry. Chemists are interested in basic substances that exist on the earth and in space, and they are interested in what these things can do and what happens when you put them together. |
| condition |
A condition is something that must happen or exist before something else can happen. [1/6 definitions] |
| creation |
the act of creating or of causing something to exist. [1/3 definitions] |
| disappear |
to exist no longer. [1/2 definitions] |
| dodo |
The dodo is a bird that does not exist on the earth anymore. It used to live on certain islands in the Indian Ocean. It had very short wings and couldn't fly. It became famous as the first animal that people realized had become extinct because of things that humans did. |
| dwell |
If a person or spirit dwells somewhere, they live there or exist there. [1/2 definitions] |
| endangered |
in danger of becoming extinct. When a type of animal is endangered, it means that few of these animals exist now, and it is possible that there will be no more of these animals in the future. [1/2 definitions] |
| establish |
to successfully start or make something that did not exist before. [1/2 definitions] |
| exist |
When something exists, it means that it is a real thing in the world. Cows, people, trees, and airplanes exist. [3 definitions] |
| extinction |
the act or process of disappearing forever or coming to a complete end, or the act or process of making something cease to exist or function. |