Definition of "torsion"

The act of turning or twisting, or the state of being twisted; the twisting or wrenching of a body by the exertion of a lateral force tending to turn one end or part of it about a longitudinal axis, while the other is held fast or turned in the opposite direction.  examples

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(mechanics) That force with which a thread, wire, or rod of any material returns, or tends to return, to a state of rest after it has been twisted; torsibility.  examples

(surgery) The stopping of arterial haemorrhage in certain cases, by twisting the cut end of the artery.  examples