Altimeter

Altimeter, al TIHM uh tuhr or AL tuh mee tuhr, is an instrument that measures altitude. Aircraft... More >>

Antipodes

Antipodes, an TIHP uh deez, are two places that lie exactly opposite each other on the globe. The... More >>

Archipelago

Archipelago, ahr kuh PEHL uh goh, is a Greek word that means chief sea. It now applies to any... More >>

Atoll

Atoll, AT ol, is a circular ring of coral in the open sea, built up on a sunken bank, or formed... More >>

Badlands

Badlands are regions of small, steep hills and deep gullies formed primarily by water erosion.... More >>

Basin

Basin is a region drained by a river and its tributaries. Tributaries are streams or other... More >>

Bay

Bay is a part of an ocean, a lake, or a similar body of water that forms an indentation in the... More >>

Bayou

Bayou, BY oo or BY oh, is a shallow, curving channel filled with slow-moving, sometimes stagnant... More >>

Beach

Beach is an accumulation of sand, pebbles, or small rocks along a shoreline. These materials may... More >>

Bog

Bog is a type of wetland in which the soil is acidic, lacking in oxygen, and low in minerals.... More >>

Bore

Bore is a wall of swift-running water formed in a bay or river mouth by a rapidly rising tide.... More >>

Canyon

Canyon, also spelled canon, is a deep valley with steep sides. A narrow canyon with nearly... More >>

Cape

Cape is a body of land that extends prominently into a lake, sea, or ocean. Capes often form at... More >>

Chaparral

Chaparral, chap uh RAL, is a region of shrubs and small trees that occurs in areas with mild,... More >>

Cliff

Cliff is a steep face of rock. Many processes of erosion form cliffs. Waves cut imposing and... More >>