Watershed

['wɔːtəʃed] or ['wɔtɚʃɛd]

Definition

(noun.) a ridge of land that separates two adjacent river systems.

Inputed by Ethel--From WordNet

Definition

(n.) The whole region or extent of country which contributes to the supply of a river or lake.

(n.) The line of division between two adjacent rivers or lakes with respect to the flow of water by natural channels into them; the natural boundary of a basin.

Checked by Andrew