n.

1. 權，權力；職權[U][（+for）][+to-v]
   Who gave you authority to do this?

   誰給你權力這樣做的？

2. 當權者，管理機構[C]
3. 官方，當局[P]
   The authorities did not interfere with us.

   當局不干涉我們。

4. 權威人士；專家，泰斗[C][（+on）]
   He is an authority on international law.

   他是一位國際法權威。

5. 權威，威信，影響力[U]
6. 授權書[S]
7. 依據，來源[U]
8. 【律】判例

n.

1. the power or right to give orders and enforce obedience.
2. a person or organization exerting control in a political or administrative sphere.
3. the power to influence others based on recognized knowledge or expertise.
   ▸an authoritative person, book, or other source.