口くちを割わる

く

ち

を

わ

る

Meanings

1

expression, godan verb (-ru)

confess; spill the beans; disclose

Idiomatic expression meaning to reveal a secret or admit something under pressure, often after being interrogated or persuaded.

警けい察さつの取とり調しらべで、ついに容よう疑ぎ者しゃが口くちを割わった。
Under police questioning, the suspect finally confessed.

彼かれはなかなか口くちを割わらなかったが、最さい後ごには真しん実じつを話はなした。

He wouldn't talk for a long time, but in the end he told the truth.

Written forms

口くちを割わる
Standard kanji spelling for this idiomatic expression.
口くちをわる
Kana spelling of the verb part; sometimes used for clarity or in casual writing.

Kanji

口mouth
割proportion, comparatively, divide

Similar words

白はく状じょうする
白状する is a more formal and direct term for confessing, often used in legal or serious contexts. 口を割る is an idiomatic, slightly colloquial expression implying that someone is made to talk.
自じ白はくする
自白する is a formal term for confession, especially in criminal contexts. 口を割る is less formal and emphasizes the act of revealing information after resistance.

Etymology

The expression 口を割る literally means 'to split one's mouth,' figuratively meaning to break silence and reveal information. The exact origin is uncertain, but it is a common Japanese idiom.