每日一词学英语(116): understudy

Welsh soprano Natalya Romaniw made a dramatic journey to her unexpected debut at the Glyndebourne Festival when the show's star fell off the stage. 威尔士女高音歌手Natalya Romaniw意外地在英国著名的一年一度的Glyndebourne歌剧节上初次亮相，因为原定角色不小心摔伤。(From BBC, 22 August 2009: Dramatic dash to debut by soprano)

When she arrived on Friday night, she had only minutes to spare to replace the understudy to Martinez. 她周五晚上到的时候，只有几分钟的时间来替换Martinez的替角。Martinez就是原定角色，即上文的“the show's star”。“the understudy to Martinez”是原定角色的替角，Natalya Romaniw是来替换这个替角进行演出的，有点绕。

understudy: (noun) (pl. -ies) ~ (to sb) an actor who learns the part of another actor in a play so that they can play that part if necessary
*She worked as an understudy to Elaine Page.
同义词：standby
under+study，表示处在学习、待命状态，即正角的替角。