expression, godan verb (-ku)
confess; come clean; spill the beans
Colloquial expression for admitting wrongdoing or revealing hidden misdeeds, often under pressure. Literally 'to vomit mud', implying the unpleasantness of the confession.
警察に泥を吐かされた。
He was forced to confess to the police.
そろそろ泥を吐いたらどうだ。
Why don't you come clean already?
Standard kanji form for this idiomatic expression.
Kana spelling for 泥, used when the kanji is avoided or for emphasis.
The phrase literally means 'to vomit mud', metaphorically likening a confession to expelling something dirty and unpleasant. The exact origin is uncertain, but it is a common colloquialism in modern Japanese.