let slip something

let (something) slip

To accidentally or inadvertently reveal some secret or important piece of information. I can't believe your sister let news of our engagement slip in front of your parents! The agent, under the influence of a powerful truth serum, let slip the names of other operatives working covertly in the area.
See also: let, slip
Farlex Dictionary of Idioms.

let ˈslip something

give somebody information that is supposed to be secret: She tried not to let slip what she knew. I happened to let it slip that he had given me $2 000 for the car.
See also: let, slip, something
Farlex Partner Idioms Dictionary
See also:
  • let (something) slip
  • let it slip
  • let slip
  • let something slip
  • let fall something
  • let (something) fall
  • a slip of the tongue
  • let (something) drop
  • let drop
  • let it drop
References in classic literature
The good man has no doubt let slip something on that subject also, though mother would deny it: 'I shall refuse,' says she.
Crime And Punishment
But the Labour leader let slip something he probably didn't mean to say, as he answered questions following the launch of his party's General Election manifesto.
Targeting voters that will actually make a difference
The female officer, codenamed Sonia, chatted up the loner in the hope he would let slip something incriminating.
The honeytrap; SPECIAL INVESTIGATION: FALL GUY FARCE Cops tried sting op to trap prime suspect Barry George Plot got go-ahead despite previous fiasco over Stagg
But Kenny Dalglish did let slip something significant in the aftermath.
Reds remain a work in progress; Dalglish's task only just begun: ANALYSIS
Someone may let slip something you have told them in confidence.
Your Stars
On the funeral of the 26-year-old, who in recent months had pitched himself against Mehsud, his brother Misabhuddin vowed to reporters that he would take revenge against Mehsud, he also let slip something else.
Pakistan's dangerous double game on war on terror exposed
However, if you get too caught up in the moment, it can lead to a red face if you let slip something that would be better kept a secret.
Your stars with Patrick Arundell
Surely Gareth is too practised a media operator to let slip something so explosive without understanding the potential impact it would have at a time when factions in the crowd were militating so openly against the manager?
So, just what is the problem at Boro?
During an interview with Simon Davies at Spurs on Friday, the Welsh international let slip something that might just constitute news to your average Cardiff City fan (if there is such a being).
Gabbs fate oh so simple to Simon
When it comes to bioterrorism and its insidious infectious diseases, we've let slip something that was once pretty good.
Combination of demands sharpens pinch of personnel shortage. (Washington Report)
I looked it up out of curiosity the other day because one of our babes had let slip something quite surprising from her mouth.
Perspective: A mind your language lesson; After Johnny Rotten turned the live television airwaves blue, Ant and Dec had to address the nation with a heartfelt apology. Sid Langley knows how they felt, but in his case the culprit was a bit less obvious. But in a society where cannabis is now a Class B drug, what about Class B words?