desert /ˈdezərt/
(noun) a large area of land that has very little water and very few plants growing on it. Many deserts are covered by sand.
Example: The Sahara is the hottest desert in the world.

ocean /ˈəʊʃn/
(noun) the mass of salt water that covers most of the earth’s surface
Example: Ocean levels are rising.

geography /dʒiˈɑːɡrəfi/
(noun) the scientific study of the earth’s surface, physical features, divisions, products, population, etc.
Example: We know more about the countries through Geography.

stream /striːm/
(noun) a small, narrow river
Example: We waded across a shallow stream.

forest /ˈfɔːrɪst/
(noun) a large area of land that is thickly covered with trees
Example: How long will it take to walk through this forest?

river /ˌrɪvər ˈfiːnɪks/
(noun) (1970-93) a US actor who became a cult figure (= a person who is fashionable with a particular group) among young people after he accidentally took too many drugs and died at the age of 23. He played sensitive characters, and his films include Stand By Me (1986), Running on Empty (1988), My Own Private Idaho (1991) and Sneakers (1992).
Example: The Nile is the longest river in the world.

glacier /ˈɡleɪʃər/
(noun) a slow-moving mass or river of ice, formed from snow on mountains or near the North Pole or South Pole
Example: He said the glaciers in the mountains of Europe now are crumbling due to global warming.

volcano /vɑːlˈkeɪnəʊ/
(noun) a mountain with a large opening at the top through which gases and lava (= hot liquid rock) are forced out into the air, or have been in the past
Example: This volcano hasn't erupted for years.

waterfall /ˈwɔːtərfɔːl/
(noun) a place where a stream or river falls from a high place, for example over a cliff or rock
Example: Angel Falls is the highest waterfall in the world.

cliff /klɪf/
(noun) a high area of rock with a very steep side, often at the edge of the sea or ocean
Example: It is a land of mountains, with steep river valleys and cliffs.

shore /ʃɔːr/
(noun) the land along the edge of the sea, the ocean or a lake
Example: I made for the shore.