an area or ridge of land that separates waters flowing to different rivers, basins, or seas 分水岭 ■an event or period marking a turning point in a course of action or state of affairs 分水岭;转折点;重要关头 these works mark a watershed in the history of music. 这些作品是音乐史上的一个分水岭。 ■(Brit.)the time after which programmes that are regarded as unsuitable for children are broadcast on television (英)开始播放儿童不宜电视节目的时间
语源
early 19th cent.: from water + shed in the sense 'ridge of high ground' (related to shed), suggested by German Wasserscheide