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).