come clean, to

To tell the whole truth, to confess. A slangy Americanism dating from the early twentieth century, it most often appeared in crime novels and pertained to confessing guilt. Listed in a collection of argot pub- lished in 1919, the term became a cliché through its overuse in murder mys- teries. P. G. Wodehouse played on it in Sam the Sudden (1925): “You’d best come clean, Soapy, and have a showdown.”