To allow fluid or gas to pass through an opening that should be sealed.
The faucet has been leaking since last month.
(of a fluid or gas) To pass through an opening that should be sealed.
No one realized that propane gas was leaking from a rusty tank in the concession area, slowly filling the unventilated room.
To disclose secret information surreptitiously or anonymously.
Someone must have leaked it to our competitors that the new product will be out soon.
Of a document, etc, produced by a company or organization, intended to be confidential but having been released to the public or the press.