- a legal proceeding mainly for the purpose of interrogating an adversary, or of examining his or her property and documents, in order to gain useful information.
- any inquiry carried on without any clearly defined plan or purpose in the hope of discovering useful information.
Origin of fishing expedition
An attempt to find useful information by asking questions at random. For example, The sales force was told to go on a fishing expedition to find out what they could about the company's competitors. This expression was taken up by lawyers to describe interrogating an adversary in hopes of finding relevant evidence and is now used more broadly still. [c. 1930]