watershed
1. [ noun ] (geography) a line that divides two adjacent river systems
Synonyms: divide water_parting
Related terms: line continental_divide Great_Divide separate
2. [ noun ] an event marking a unique or important historical change of course or one on which important developments depend
Synonyms: turning_point landmark
Examples:

"the agreement was a watershed in the history of both nations"

Related terms: juncture road_to_Damascus Fall_of_Man
Similar spelling:   Waters
  water-washed
  Watters
  Waiters
  watercourse
  water-shield
  waders
  waterside
  water-wash
  water_shrew
  water_chute
  Waterson
  waitress
  watergate
  waterskin
  water_ice
  water_gas
  Watterson
  watercress
  waterspout
  Waterhouse
  watercolor
  water-cooled
  water_gate
  water_gage