watershed Meaning, Definition & Usage

  1. noun a ridge of land that separates two adjacent river systems
    water parting; divide.
  2. noun the entire geographical area drained by a river and its tributaries; an area characterized by all runoff being conveyed to the same outlet
    catchment basin; catchment area; basin; river basin; drainage area; drainage basin.
    • flood control in the Missouri basin
  3. noun an event marking a unique or important historical change of course or one on which important developments depend
    landmark; turning point.
    • the agreement was a watershed in the history of both nations

WordNet

Wa"ter*shed` noun
Etymology
Cf. G. wasserscheide; wasser water + scheide a place where two things separate, fr. scheiden to separate.
Definitions
  1. The whole region or extent of country which contributes to the supply of a river or lake.
  2. 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.

Webster 1913