watershed
(noun)
noun
1. a ridge of land that separates two adjacent river systems
Similar word(s): divide
Definition categories: location, line
2. the entire geographical area drained by a river and its tributaries; an area characterized by all runoff being conveyed to the same outlet
Similar word(s): basin
Definition categories: location
3. an event marking a unique or important historical change of course or one on which important developments depend
- the agreement was a watershed in the history of both nations
Similar word(s): landmark