prologue
/ˈprəʊlɒg/( <美> prolog)
noun
1- a separate introductory section of a literary or musical work序言; 序诗; 序曲：
the suppressed prologue to Women in Love.
小说《恋爱中的女人》中那压抑的序言。
1.1
- an event or action that leads to another event or situation引出某种情况的事件（或行动）; 开端序幕：
the events from 1945 to 1956 provided the prologue to the post-imperial era.
1945到1956年发生的一系列事件拉开了后帝国时代的帷幕。
1.2
- (in professional cycling) a short preliminary time trial held before a race to establish a leader（职业自行车赛前举行的）领头车选拔赛。
1.3
- the actor who delivers the prologue in a play（在剧中）念开场白的演员。
词源
Middle English: from Old French，via Latin from Greek prologos,from pro- 'before'+logos 'saying'.