avalanche /ˈævəlænʃ/ noun

1. A large mass of snow, ice, and rocks that falls down the side of a mountain.
2. A sudden and overwhelming arrival of something in great quantity.

cave /keɪv/ noun, verb

noun:

1. A large hole in the side of a hill or under the ground.
2. A place where people live that is built under the ground.
3. A large underground chamber in a cave system.

verb:

1. To explore caves.
2. To make a cave or hole in something.

cliff /klɪf/ noun

1. A high, steep rock face that forms a boundary between two areas of land or between land and sea.
2. A steep drop in the ground or in the level of something.

continent /ˈkɒntɪnənt/ noun

1. One of the seven main areas of land on the earth’s surface.
2. A large area of land that is not separated by sea from other similar areas.
3. The land mass of Europe, Asia, and Africa considered as a single entity.

delta /ˈdeltə/ noun

1. An area of low, flat land, sometimes shaped like a triangle, where a river divides into several smaller rivers before it flows into the sea.
2. A triangular piece of land at the mouth of a river.

glacier /ˈɡleɪsɪə(r)/ noun

A large mass of ice that moves slowly down a mountain valley. A slow-moving mass or sheet of ice formed by the accumulation and compaction of snow on mountains or near the poles.

landscape /ˈlændskeɪp/ noun

1. A view of rural scenery, including fields, forests, hills, and mountains.
2. The appearance of an area of land, including its physical features, natural resources, and historical and cultural attributes.

oasis /əʊˈeɪsɪs/ noun

1. A small area in a desert where there is water and plants.
2. A pleasant, peaceful place or situation in the middle of a difficult or unpleasant one.

plain /pleɪn/ noun, adjective

noun:

1. An area of flat, level land.
2. A large open area of land with no trees or buildings.

adjective:

1. Simple and not complicated.
2. Clear and easy to understand.

plateau /ˈplætəʊ/ noun

1. A large, flat area of land that is higher than the land around it.
2. A state of little or no change after a period of activity or progress.

seismic /ˈsaɪzmɪk/ adjective

1. Related to or caused by earthquakes or other vibrations of the earth.
2. Related to or caused by the sudden and powerful movements of the earth’s crust.

swamp /swɒmp/ noun, verb

noun:

1. An area of low, wet land where the ground is soft and muddy.
2. A difficult or unpleasant situation that is hard to get out of.

verb:

1. To cause something to sink or become stuck in mud or wet ground.
2. To overwhelm or inundate with a large quantity of something.

terrain /təˈreɪn/ noun

1. The physical features of a particular piece of land.
2. An area of land or a type of land with particular physical features.