名詞 informant:

1. a person who supplies information
   同義詞：source
2. someone who sees an event and reports what happened
   同義詞：witness, witnesser

1. Police hurried to the address supplied by their informant, only to learn that their bird had flown less than an hour before.
   警察急忙趕到告密者提供的地址處，只獲悉他們要捉的人一小時不到前已逃走了。
2. A person, especially an informant, who communicates something.
   傳遞信息的人傳達某事的人，尤指密告者
3. The journalist did not want to reveal the identity of his informant.
   那個新聞工作者不想透露消息提供人的身分。

in.form.ant

n.（名詞）

One that gives information.
通知者：提供消息的人
One who informs against others; an informer.
告密者：檢舉他人的人；告密的人
One who furnishes linguistic or cultural information to a researcher.
為研究者提供語言或文化方面信息的人