In Reply to: Over a barrel posted by Leslie E. DeLong on July 05, 2009 at 15:55:
: What is the origin of phrase "to be over a barrel?"
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Apparently it is of American origin, and the most likely derivation comes from a form of punishment, or humiliation, involving binding someone's hands and feet and rolling them over a barrel.
A person in that situation is completely at the mercy of his captors/tormentors and thus is had 'over a barrel'.