protagonist

n.

1. (戏剧的)主角
2. (故事的)主人公; 现实事件(尤指冲突和争端的)主要参与者, 主要人物
3. 领导者; 倡导者; 拥护者
   • She was herself a vehement protagonist of sexual equality.
     她本人就热心提倡男女平等。