noun The area of land that drains into a particular river, lake, or sea.
- Farmers upstream can affect water quality throughout the whole watershed.
- Rain falling on the hills feeds a watershed that supplies the whole town.
- Conservation groups planted trees to protect the watershed around the reservoir.
noun A turning point or critical moment that marks a major change.
- Moving abroad was a watershed in her life, and nothing was quite the same afterward.
- The court's decision marked a watershed in how schools deal with bullying.
adj Marking a major, defining change or development.
- The invention of the internet was a watershed moment in how people communicate.
- It was a watershed year for the company, doubling its revenue.
- That watershed discovery changed how doctors treat the illness for ever.
- She called the move a watershed decision that reshaped her whole career.
