主角:
1. leading role
2. lead
Relative explainations:
<leading character> <leading actor> <protagonist> <principal> <cardinal angle> <starred> <principal angle> <leading star>
Examples:
1. 当她还是一个十六岁的无名少女时，导演选中她演主角。
The director cast her in a leading part when she was a young unknown of 16.
2. 他一直在讨好导演, 想在剧中扮演主角.
He has been courting the director, hoping to get the leading role in the play.
3. 演主角的是一个毫无名气的演员.
The leading role is played by a complete unknown.
4. 主角演员患病, 由替角代替演出.
The understudy was substituted when the leading actor fell ill.
5. 寓言常以动物为主角。
Fables often have animals as the main characters.
男主角:
1. hero
2. leading man
3. starring actor
4. male lead
5. leading men
Examples:
1. 当男主角策马向夕阳驰去时，尾声音乐逐渐消失。
The closing music fades out when the hero rides off into the sunset.
2. 摄像机向男主角靠近，准备拍一组特写镜头。
The camera moved in on the hero for a close-up sequence.
3. 男主角的表现是高於生活的。
The hero appears as a larger-than-life character.
4. 浪漫小说中最不真实的事情就是：女主角总是嫁给了意中人，男主角总是娶到了心上人。
The most unrealistic thing about romantic fiction is that the heroine always marries Mr Right and the hero always marries Miss Right.
女主角:
1. heroine
2. prima donna
3. the leading actress
4. preem
5. female lead
Examples:
1. 她被选定在这部影片中扮演女主角。
She was chosen to play the heroine in this film.
2. 影片的女主角是一位老妇人。
The heroine of the film is an aged woman.
3. 这部电影以女主角的死告终。
The film ends with the death of the heroine.
4. 女主角退场.
The heroine makes her exit (from the stage).