|Origin:||water + shed 'line of high ground' (16-21 centuries) (from Old English scead 'separation'); suggested by German wasserscheide|
an event or time when important changes happen in history or in your life [= turning point]
The 1932 election represented a watershed in American politics.
watershed decision/case etc
a watershed case on pension rights
2 British EnglishAMT
the time in the evening after which television programmes that are not considered suitable for children may be shown in Britain
the high land separating two river systems