Definition of watershed in English:

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Pronunciation: /ˈwɔːtəʃɛd/


1An area or ridge of land that separates waters flowing to different rivers, basins, or seas.
Example sentences
  • In the Marin watershed on Pumpkin Ridge, Davidson showed me a site where Rizzo and other scientists had injected some healthy coast live oaks with P. ramorum.
  • O'Grady and Geslin were still in the lead, some hundred miles into the stage, when the peloton climbed steadily into the area known as Le Forez, the watershed between the rivers Saone and Rhone.
  • These included aggregations sampled along parallel watersheds in the Madawaska Highlands for examining fine geographic scale population structure.
1.1An area or region drained by a river, river system, or other body of water.
Example sentences
  • The Penobscot River drains the largest watershed in Maine and is the U.S. Fish and Wildlife Service's flagship river for the restoration of Atlantic salmon in the country.
  • These sources are particularly important because the rivers drain watersheds that don't receive much summer rainfall and where rates of evaporation are relatively high.
  • Opponents of the project worry the resulting salty waste water will find its way into the local watershed and into river systems leading south into Montana.
2An event or period marking a turning point in a situation: these works were a watershed in the history of music
More example sentences
  • This essay starts from the observation that the 1993 general election marked a major watershed in Canadian party politics.
  • Publication of this story marks a watershed in American political history.
  • The Kosovo War was a watershed event that profoundly changed the political situation.
2.1British The time after which programmes that are regarded as unsuitable for children are broadcast on television: the 9 p.m. watershed
More example sentences
  • Why watch a programme, broadcast well after the watershed, if you know you are going to be offended by it?
  • Where television has a watershed, and a schedule you can check, the internet is a 24/7 whirlpool of information devoid of any moral context.
  • Warnings about the language will be given and it will be broadcast well after the watershed.


Early 19th century: from water + shed in the sense 'ridge of high ground' (related to shed2), suggested by German Wasserscheide.

For editors and proofreaders

Line breaks: water|shed

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