let something slip

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

let something slip

1 reveal something inadvertently in the course of a conversation. 2 fail to take advantage of an opportunity.See also: let, slip, something