watershed

Etymology

From water +‎ shed, a calque of German Wasserscheide, a compound of Wasser (“water”) + scheiden (“to divide”).

Pronunciation

• (UK) IPA^(key): /ˈwɔːtəʃɛd/
• (US) enPR: wôʹtərshĕd, IPA^(key): /ˈwɔtɚʃɛd/

• Audio (US):

  (file)

• Hyphenation: wa‧ter‧shed

Noun

watershed (plural watersheds)

1. (hydrology, UK, Ireland, Australia, New Zealand) The topographical boundary dividing two adjacent catchment basins, such as a ridge or a crest.

   Synonyms: water parting, drainage divide, water divide, divide

2. (hydrology, US, Canada) A region of land within which water flows down into a specified body, such as a river, lake, sea, or ocean; a drainage basin.

   Synonyms: catchment basin, catchment, catchment area, drainage area, river basin, water basin

3. (figurative) A critical point marking a change in course or development.

   Synonyms: turning point, crossroads

   • 2009 [2007], David A. Weintraub, Is Pluto a Planet?: A Historical Journey through the Solar System, Princeton, NJ: Princeton University Press, →ISBN, page 115:

     In the minds of many, 1847 was a watershed year during which Ceres, Pallas, Juno, Vesta, and Astraea were reclassified as asteroids.

   • 2021 November 17, Anthony Lambert, “How do we grow the leisure market?”, in RAIL, number 944, page 34:

     Coronavirus has been a watershed for the railways. It has accelerated the decline of season tickets and reduced business travel after years of steadily rising passenger numbers.

   • 2023 February 7, Cade Metz, Karen Weise, “Microsoft Throws a Coming-Out Party for A.I.”, in The New York Times‎, →ISSN:

     In a 2,000-word blog post published ahead of the press event, Brad Smith, Microsoft’s president, called this a “watershed year” and acknowledged the potential downsides, calling for “wide-ranging and deep conversations” on the issues.

4. (Canada, British, television, radio) The time during the day which material of a more adult nature (e.g., violence, swear words, or sex) may be broadcast on television or radio, either one permitted by law or one contrived from convention (e.g. when children are not watching).

   Synonym: (US) safe harbor

Adjective

watershed (not comparable)

1. Serving to mark a significant development, change in direction, etc.
   • 2018, James Lambert, “Anglo-Indian slang in dictionaries on historical principles”, in World Englishes, volume 37, page 251:

     Green's Dictionary of Slang is a watershed publication in the annals of slang lexicography, being, beyond doubt, the most comprehensive scholarly dictionary of slang ever published.

Anagrams

• draw sheet, drawsheet