| Term | Definition |
| plateau | a large raised area of mostly level land. |
| isthmus | a strip of land with water on both sides that joins two larger bodies of land. |
| pampas | flat grassland regions. |
| rain forest | a dense evergreen forest that has abundant rainfall year-round. |
| Amazon River | a long river in northern South America. |
| tributary | a river or stream that flows into a larger river. |
| El Nino | a warming of the ocean water along the western coast of South America. |
| elevation | the height above sea level. |
| economy | the ways in which goods and services are produced and made available to people. |
| natural resources | things found in nature that people can use to meet their needs. |
| hydroelectricity | electric power produced by rushing water. |
| one-resource economy | a country's economy based largely on one resource or crop. |
| diversify | add variety. |