Definition: An oceanic island, often having a characteristic ring-like shape surrounding a lagoon. Atolls are formed when coral reef grows around a volcanic island that later subsides into the ocean.
Definition: A tract of alluvium formed at the mouth of a river where the deposition ofsome of its load exceeds its rate of removal, crossed by the divergent channels (distributaries) of the river.
Definition: A tract of crop or grazing land, as well as the group of buildings with and often surrounding a farmhouse, including barns, sheds, and other outbuildings, used for agricultural production.