prologue
Word family nounprologueverbprologize
pro·logue /ˈprəʊlɒɡ $ ˈproʊlɒːɡ, -lɑːɡ/ noun [countableC usually singular] 2 literaryBEGINNING an act or event that leads to a more important event 〔重大事件的〕开端,序幕prologue to a prologue to the final abandonment of trams in London 伦敦最终弃用有轨电车的开端
Origin prologue (1300-1400) Old French Latin prologus “first part of a play”, from Greek, from pro- “before” + legein “to speak”