watershed

watershed — noun

1. a moment or happening that causes a lasting shift in how things develop, so that

1.nounB2
Definition

a moment or happening that causes a lasting shift in how things develop, so that the situation afterwards is fundamentally different from before.

Example

The peace agreement was a watershed in the region's troubled history.

watershed + in + something — signals a context or field being transformed

For Lan, graduating from university marked a watershed that opened new career paths.

Common collocations
  • watershed in
  • watershed for
  • watershed moment
  • watershed event
  • mark a watershed
  • represent a watershed
Synonyms
  • turning point

    more common in everyday speech; emphasises a change of direction rather than a permanent before/after divide

  • milestone

    focuses on progress and achievement along a path, not necessarily a dramatic shift

  • landmark

    emphasises that the event is notable and historic, but does not imply a complete break with the past

Grammar Patterns

watershed + in + noun phrase

watershed + for + noun phrase

watershed moment/event

Usage Note

Often used with the verb 'mark' or 'represent'. Frequently followed by 'in' to name the area of life or history that changed.

Common Mistakes

The ceremony was a watershed celebration for the school.
The ceremony was a watershed event for the school.
'Watershed' describes events that cause change, not just any celebration.

2. a ridge or line of high ground that separates two different river systems, causi

2.nounC1
Definition

a ridge or line of high ground that separates two different river systems, causing water to flow in opposite directions on each side.

Example

The Continental Divide is the best-known watershed in North America.

the watershed — definite article is standard

Hikers reached the watershed and saw streams flowing toward two different oceans.

Common collocations
  • the watershed between
  • form a watershed
  • natural watershed
  • continental watershed
Synonyms
  • divide

    preferred term in American English for the same geological feature

  • ridge

    broader term — not all ridges are watersheds; a ridge only functions as a watershed if it separates drainage basins

Grammar Patterns

the + watershed + between + noun phrase + and + noun phrase

Usage Note

Common in geography textbooks and hiking contexts. The definite article 'the' is almost always used before 'watershed' in this sense.

3. in the United Kingdom, the time at 9 p.m. after which television broadcasters ar

3.nounB2
Definition

in the United Kingdom, the time at 9 p.m. after which television broadcasters are permitted to show programmes containing content unsuitable for children.

Example

The documentary contained strong language and aired after the watershed.

after the watershed — signals UK TV timing rule

Baraka's children were asleep by 8:30, well before the watershed.

before the watershed — opposite timing

Common collocations
  • after the watershed
  • before the watershed
  • past the watershed
  • watershed hour
  • the watershed
Synonyms
  • watershed hour

    less common but used in official broadcasting guidelines

Grammar Patterns

after/before the watershed

past the watershed

the + watershed

Usage Note

This meaning is specific to the United Kingdom and is almost always used with the definite article: 'the watershed'. The most common prepositions are 'before' and 'after'.

Common Mistakes

The movie was too violent to show after the watershed.
The movie was too violent to show before the watershed.
Adult content goes after the watershed, not before it.

4. all the land that collects rain and directs it into one particular river, lake,

4.nounC1
Definition

all the land that collects rain and directs it into one particular river, lake, or sea.

Example

The Amazon watershed covers millions of square kilometres across South America.

[proper noun] + watershed — naming a specific drainage basin

Pollution from factories upstream affects the entire watershed downstream.

Common collocations
  • the watershed of
  • local watershed
  • protect the watershed
  • watershed area
  • watershed management
Synonyms
  • drainage basin

    the preferred term in formal hydrology; equally common in academic writing

  • catchment area

    more common in British English and often used for smaller areas such as a reservoir's supply zone

  • river basin

    specifically refers to the area drained by a river and its tributaries

Grammar Patterns

the + noun phrase + watershed

watershed + of + noun phrase

Usage Note

Often used in environmental science, conservation, and water management contexts. Can be replaced by the term 'drainage basin' or 'catchment area' in most contexts.

Synonym discussion

Sense: noun/1

All four words describe important moments or events, but each carries a different nuance. 'Watershed' emphasises a sharp before-and-after contrast — things on one side are fundamentally different from things on the other. 'Turning point' focuses on a change of direction rather than a permanent divide; a situation can turn and then turn back. 'Milestone' highlights progress along a known path, like achievements in a career or project, without implying a break from the past. 'Landmark' stresses that an event is historically notable or widely recognised, but does not necessarily mean the course of events changed. 'Crossroads' suggests a moment of choice between possible futures. For example, signing a peace deal is a watershed (the conflict is over for good); passing a final exam is a milestone (a step forward in an expected sequence); a famous court case is a landmark (it sets a notable precedent).

turning pointmilestonelandmark ↗crossroads

Common collocations

Nouns

Phrases

  • mark a watershed
  • represent a watershed
  • reach a watershed
  • beyond the watershed

Prepositions

Etymology

Old EnglishEnglish

Formed in English from 'water' and 'shed' (an old word meaning 'to separate' or 'to divide', from Old English 'sceadan'). Originally used in geography to describe a ridge that separates two river systems. The figurative meaning — a moment or event that causes a decisive change — appeared in the mid-19th century.