Tra từ watershed - Từ điển Oxford Advanced Learner 8th

▪ I. water·shed [watershed watersheds] BrE [ˈwɔːtəʃed] NAmE [ˈwɔːtərʃed] NAmE [ˈwɑːtərʃed] noun
1. countable ~ (in sth) an event or a period of time that marks an important change
•The middle decades of the 19th century marked a watershed in Russia's history.
2. countable a line of high land where streams on one side flow into one river, and streams on the other side flow into a different river
3. the watershedsingular (in Britain) the time before which programmes that are not considered suitable for children may not be shown on television
•the 9 o'clock watershed

Word Origin:
early 19th cent.: from ↑water + shed in the sense ‘ridge of high ground’ (related to the verb ↑shed), suggested by German Wasserscheide.

Example Bank:
•The 19th century marked a watershed between the country's agricultural past and its industrial future.
•The completion of this project was a watershed event in the company's history.
•The granting of the vote represented a watershed for the rights of women.
•With the strike, a historical watershed in the development of the trade union movement was reached.
•a watershed moment in recent music history
•a watershed year for Japan
•The middle decades of the 19th century marked a watershed in Russia's history.

▪ II. the watershed [the watershed] BrE NAmE (alsothe nine o’clock watershed)noun [sing]
(in Britain) 9.00 p.m, the time before which the main television stations agree not to broadcast programmes that are not suitable for children, e.g. because they include too much sex, violence or bad language. If this rule is broken, complaints can be made to an official organization, ↑Ofcom.
See also: ↑nine o'clock watershed