dead letter box


Also found in: Thesaurus, Encyclopedia, Wikipedia.

dead letter box

or

dead letter drop

n
(Communications & Information) a place where messages and other material can be left and collected secretly without the sender and the recipient meeting
References in periodicals archive ?
We should have done a dead letter box or brush contact on the riverside.
What, for example, was an Irish politician doing with an office in eastern Europe, described in the media as looking less like a place of business than the sort of dead letter box one finds in espionage novels?