informant

Compared meaning: a person who gives information (noun).

比较义项：提供消息或情报的人（名词）。

• source

  Source is the neutral, general term for a person, often unnamed, who supplies information to a journalist, researcher, or investigator; it does not imply secrecy or wrongdoing, as in "according to a source."

  source（消息来源）是较为中性、泛指的说法，指为记者、研究者或调查者提供信息的人，常常是匿名的，并不必然涉及秘密或不法行为，常见于“据消息人士透露”这类表达中。

  A newspaper report quoted an anonymous source close to the negotiations.

  一篇报道引用了一位接近谈判的匿名消息来源的话。

• informant 本词

  Informant specifically means someone who secretly supplies information to the police or other authorities, usually about criminal activity and often in exchange for money or protection; it carries a stronger, more negative sense of betrayal.

  informant（线人、告密者）专指秘密向警方或其他当局提供信息的人，通常涉及犯罪活动，且常是为了获得报酬或保护；这个词带有更强烈、更负面的“背叛”意味。

  The detective paid his informant for tips about the drug ring.

  那位警探花钱让他的线人提供有关毒品团伙的情报。

Source and informant both mean someone who gives information. Source is neutral, often a person who informs a journalist or researcher. Informant secretly informs the police, often meaning betrayal. Source can also mean where something comes from; that is not compared here.

这两个词都表示“提供消息的人”，但语气和场合不同：source 较为中性，泛指为记者或研究者提供信息的人；informant 则强调秘密地向警方或当局告密，且常带有负面的“告密者”意味。这里不比较 source 的其他意义，例如“（水等的）来源、出处”。