What is the becoming stiff or rigid; the state of being rigid; rigidity; stiffness; hardness. The rest his look Bound with Gorgonian rigor not to move. Milton called?

rigor — The becoming stiff or rigid; the state of being rigid; rigidity; stiffness; hardness. The rest his look Bound with Gorgonian rigor not to move. Milton. (Webster's 1913.)

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