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