1. 杰作;名著
    A masterpiece is an extremely good painting, novel, film, or other work of art.

    e.g. His book, I must add, is a masterpiece.
           我必须补充一点：他的书是一部杰作。
    e.g. ...masterpieces by artists like Rembrandt, Raphael and Ingres.
           伦勃朗、拉斐尔和安格尔这些画家的杰作

2. (画家、作家或作曲家的)最佳作品，代表作
    An artist's, writer's, or composer's masterpiece is the best work that they have ever produced.

3. 典范
    A masterpiece is an extremely clever or skilful example of something.

    e.g. The whole thing was a masterpiece of crowd management.
           整件事情就是人群管理的典范。