Muckraker

Noun

 * 1) 🇺🇸 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.
 * 2)  A sensationalist, scandal-mongering journalist, one who is not driven by any social principles.
 * 3) 🇺🇸 One of a group of American investigative reporters, novelists and critics of the Progressive Era (the 1890s to the 1920s)

Derived terms

 * muckraking

Thesaurus
Thersites, annotator, backbiter, belittler, calumniator, captious critic, carper, caustic critic, caviler, censor, censurer, cognoscente, commentator, commenter, connoisseur, critic, criticaster, criticizer, critickin, criticule, cynic, debunker, decrier, defamer, deflater, depreciator, derogator, detractor, disparager, editor, faultfinder, hatchet man, knocker, libeler, literary critic, man of letters, mudslinger, railer, reviewer, scholiast, slanderer, smellfungus, social critic, textual critic, traducer

Etymology
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.

Translations

 * French: