watershed
Americannoun
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Chiefly British. the ridge or crest line dividing two drainage areas; water parting; divide.
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the region or area drained by a river, stream, etc.; drainage area.
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Architecture. wash.
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an important point of division or transition between two phases, conditions, etc..
The treaty to ban war in space may prove to be one of history's great watersheds.
adjective
noun
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the dividing line between two adjacent river systems, such as a ridge
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an important period or factor that serves as a dividing line
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A continuous ridge of high ground forming a divide between two different drainage basins or river systems.
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The region enclosed by such a divide and draining into a river, river system, or other body of water.
Discover More
By extension, a “watershed” is a critical point that serves as a dividing line: “The parties reached a watershed in the contract negotiations.”
Other Word Forms
Noun Inflected Forms
Etymology
Origin of watershed
Explanation
A watershed is a turning point, or historic moment. The day you got your braces off might have been a watershed moment in your life. Watershed is a geographical term, originally. The area that drains into a single river is the watershed for that river. Watershed can also mean a ridge, like that formed by a chain of mountains, which sends water to two different rivers on either side. It's from this meaning that watershed came to mean a turning point or dividing line in social life.
Vocabulary lists containing watershed
March: Book One
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100 SAT words Beginning with W,X,Y, and Z
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Physical Geography - Middle School
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
NUH said the review was a "watershed moment" and it was "committed to creating a better maternity service" for women, babies and families in its care.
From BBC ● Jul. 20, 2026
Ronald Reagan’s diagnostic revelation in 1994 was a watershed event in promoting awareness of Alzheimer’s disease and has been followed by many more high-profile disclosures.
From The Wall Street Journal ● Jun. 20, 2026
Snowfall in the Gila River watershed was exceptionally scarce, leaving mountain snowpack at just 2 percent of the 1991-2020 March median.
From Science Daily ● Jun. 18, 2026
“Overall, SpaceX going public is an important watershed moment for the broader tech sector in our view as this AI Revolution and data takes this next step forward,” Ives said.
From MarketWatch ● Jun. 14, 2026
The pass at the watershed was five thousand feet and it was going to be very cold.
From "The Road" by Cormac McCarthy
When exploring the watersheds east of Cuzco, Peru, he writes, Miller was “overawed by the tropical forest canopy stretching to infinity before him.”
From The Wall Street Journal ● Apr. 17, 2026
Large watersheds are far more common on Earth than on Mars.
From Science Daily ● Dec. 31, 2025
Of these, 16 formed interconnected watersheds covering at least 100,000 square kilometers.
From Science Daily ● Dec. 31, 2025
“Building the snowpack on hydrated watersheds will help us avoid losing potential spring runoff to dry soils later in the season,” Anderson wrote in an email.
From Los Angeles Times ● Nov. 24, 2025
Such places, the watersheds of the great coniferous forests of spruce and balsam, of hemlock and pine, provide the kind of spawning grounds that salmon must have in order to survive.
From "Silent Spring" by Rachel Carson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
