口(くち)を滑(すべ)らす

くちをすべらす
expression
to let something slip; to say something by mistake
communication
1. to let something slip; to blurt out; to make a slip of the tongue
To accidentally say something that should have been kept secret or that one did not intend to reveal. Literally 'to let one's mouth slide.'
つい口(くち)を滑(すべ)らせてしまった。
I accidentally let it slip.
秘密(ひみつ)を知(し)っていたが、口(くち)を滑(すべ)らせてしまった。
I knew the secret but ended up blurting it out.
サプライズパーティーのことを口(くち)を滑(すべ)らせて本人(ほんにん)に言(い)ってしまった。
I accidentally let it slip to the person about the surprise party.

Usage

This expression is almost always used with てしまう to convey the accidental, regrettable nature of the slip. The subject is always the person who blurted something out.

Common patterns

The verb 滑(すべ)らす is a godan verb. In practice, the te-form 口(くち)を滑(すべ)らせて is the most common form encountered.

Similar words

Related Words

Compare: 口(くち)を挟(はさ)む (to butt in)
Compare: 失言(しつげん) (to make a verbal gaffe)
general
Added 2026.3.5 18:38 · Revised 2026.9.2 13:01
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