内 通 者(ないつうしゃ)

ないつうしゃ

noun

informant; inside collaborator; mole

1. inside collaborator; mole; secret informant

Someone who secretly passes information to the opposing side while remaining part of their own group. Strongly negative — the word implies betrayal, not whistleblowing.

組織(そしき)に内通者(ないつうしゃ)がいた。

There was a mole inside the organization.

内通者(ないつうしゃ)を探(さが)し出(だ)すのに時間(じかん)がかかった。

It took time to track down the inside collaborator.

作戦(さくせん)が事前(じぜん)に漏(も)れていたことから、内通者(ないつうしゃ)の存在(そんざい)が疑(うたが)われた。

Because the plan had leaked in advance, the presence of a mole was suspected.

Formed from 内通(ないつう) (secret communication with the enemy) plus 〜者(しゃ) (person who). Most at home in war stories, crime fiction, and corporate-espionage reporting.

Common collocations

内通者(ないつうしゃ)を疑(うたが)う: to suspect someone of being a mole
内通者(ないつうしゃ)狩(が)り: a hunt for the informant
敵(てき)の内通者(ないつうしゃ): the enemy's inside man

Similar words

密告者(みっこくしゃ): informer — reports others to the authorities; not necessarily an insider serving a rival
裏切(うらぎ)り者(もの): traitor — the everyday word, broader and not limited to passing information
スパイ: spy — planted from outside, whereas an 内通者(ないつうしゃ) is a genuine member who turns

Related Words

Compare: 密告者(みっこくしゃ) (informer)

Compare: 裏切(うらぎ)り者(もの) (traitor)

Compare: スパイ (spy)

Compare: 密偵(みってい) (spy)

general

Added 2026.8.2 18:20 · Revised 2026.9.2 13:02

30000/30337_naitsuusha