protagonist

The understudy be substitute when the leading actor fall Ill

主角演员患病, 由替角代替演出

The understudy is substituted when the leading actor falls ill.

主角演员患病，由替角代替演出。

The understudy was substituted when the leading actor fell ill.

主角演员患病, 由替角代替演出.

The leading player is ill. Let his understudy to appear on the scene.

主角演员病了, 让他的替角出

The leading lady is to be played by a well-known actress.

女主角将由名演员担任。

the leading comedian in a burlesque show.

在滑稽表演中演主角的喜剧演员。

leading male role in a pantomime,traditionally played by a woman

童话剧中的男主角（一向由女演员扮演）.

the principal boy [ girl ]

(哑剧中)扮演男[女]主角的女演员

The leading role is played by a complete unknown.

演主角的是一个毫无名气的演员.

She is the leading lady in the play.

她是剧中扮演女主角的演员。

A person having a leading or starring role.

主要演员，主角担任领导或主要角色的人

The last show headlined another performer.

最后一场演出推出了另一个演员演主角。

A principal woman dancer in a ballet company.

芭蕾舞女主角芭蕾舞团的主要女演员

The cast, I think, the leading actor, the leading actress playing opposite him and everyone else.

我想是演员们，如男主角、女主角以及其他人。

The leading actor is a good actor but the leading lady seems a little stiff.

男主角是一位好演员,但女主角显得有些呆板。

The producer cast leading actors in the parts.

制片人给主要演员分配角色。

And the young actor Adrien Brody is the fifth Best Actor nominee.

年轻的演员阿德里安?布劳迪是第5位获得最佳男主角提名的演员，

change the role of(an actor)

改变（演员）的角色