- (US) One who investigates and exposes issues of corruption that often violate widely held values; e.g. one who exposes political corruption or the poor conditions in prisons.
- (UK) A sensationalist, scandal-mongering journalist, one who is not driven by any social principles.
- (US, historical) One of a group of American investigative reporters, novelists and critics of the Progressive Era (the 1890s to the 1920s)
Believed to have been coined following a 1906 speech by United States President Theodore Roosevelt, in which he likened the investigative journalist to ‘the Man with the Muck-rake’, a character in John Bunyan's Pilgrim's Progress.