| Term | Definition |
| contiguous | next to each other |
| climate | the kind of weather a place has over a long time |
| region | an area in which many features are similar |
| mountain range | a group of connected mountains |
| relative location | the position of one place compared to other places |
| erosion | the gradual wearing away of the Earth's surface |
| continent | one of Earth's seven largest land masses |
| prairie | an area of flat or rolling land covered mostly by grasses |
| population | the number of people who live in an area |
| environment | the surroundings in which people, plants, and animals live |
| landform region | a region that has similar landforms throughout |
| inlet | any area of water extending into the land from a larger body of water |
| gulf | a large inlet |
| elevation | the height of land in relation to sea level |
| sound | a long inlet that seperates offshore islands from the mainland |
| natural vegetation | the plant life that grows naturally in a place |
| tributary | a stream or river that flows into a larger stream or river |
| arid | dry |
| river system | a river and its tributaries |
| tundra | a cold, dry region where trees cannot grow |
| drainage basin | the land drained by a river system |
| land use | how the land is used |
| fall line | a place where the land drops sharply, causing rivers to form waterfalls or rapids |
| natural resource | something found in nature, such as soil, plants, water, or minerals that people can use to meet their needs |
| renewable resource | resources that can be made again by people or nature |
| nonrenewable resource | resources that cannot be made again by people or nature |
| modify | to change |
| irrigation | the use of canals, ditches, or pipes to move water |
| efficiency | using less energy to do the same tasks |