RACK, n. An argumentative implement formerly much used in persuading devotees of a false faith to embrace the living truth. As a call to the unconverted the rack never had any particular efficacy, and is now held in light popular esteem.

Ambrose Bierce (1842–1914?) American writer and journalist

“Rack,” The Devil’s Dictionary (1911)
    (Source)

Originally published in the "Cynic's Word Book" column in the New York American (1906-06-29).