watershed
noun uk/ˈwɔː.tə.ʃed/ us/ˈwɑː.t̬ɚ.ʃed/
(BIG CHANGE)
[ S ]（标志重大变化的）转折点，分界线，分水岭
an event or period that is important because it represents a big change in how people do or think about something
The year 1969 was a watershed in her life - she changed her career and remarried. 1969年是她人生的一个转折点——她改了行，也再婚了。
(HIGH GROUND)
[ C ] geography specialized分水岭，分水界
an area of high ground from which water flows down to a river
(TELEVISION)
the watershed[ S ] UK 分水岭时间（在英国通常指晚上9点以后电视可以播放儿童不宜节目的时段）
in Britain, the time in the evening, usually 9 p.m., when television programmes that are not suitable for children may start to be shown