a.

1. 不能相信的，不可信的[Z]
   The plot of the book is incredible.

   这本书的情节叫人难以相信。

2. 【口】难以置信的；惊人的；极妙的
   For such a tiny woman she had an incredible appetite.

   对这么一个小个子女人来说，她的胃口大得令人难以置信。

adj.

1. impossible to believe.
2. difficult to believe; extraordinary.
   ▸informal amazingly good.