名詞 observer:

1. a person who becomes aware (of things or events) through the senses
   同義詞：perceiver, percipient, beholder
2. an expert who observes and comments on something
   同義詞：commentator

1. He is an acute observer.
   他是個敏銳的觀察家。
2. Having the back showing or in view of the observer.
   背面的顯露出背面的或背對觀察者的
3. A person stationed in a given location as a spy or an observer.
   間諜作為間諜或觀察者處在給定位置的人
4. The driver is a poor observer of speed restrictions.
   這個司機是個不遵守速度限制的人。
5. They sent her there as an observer.
   他們派她去那做觀察員。

ob.serv.er

n.（名詞）
One that observes:
遵守者，觀察者：遵守的人：
例句：
an observer of local customs; observers of religious holidays.
當?shù)亓曀椎淖袷卣?；宗教?jié)日的觀察者

A delegate sent to observe and report on the proceedings of an assembly or a meeting but not vote or otherwise participate.
觀察團：一個代表團，派去觀察并報告集會或會議進展，但不投票或參與其它活動

A crew member on a military aircraft who makes observations.
觀察員：軍用飛機上進行觀察或偵察的機員
A member of an armed force who watches and reports from an observation post.
觀察員：軍隊中一員，從觀察站觀察并報告情況