Dictionary:

rigidity

  (rĭ-jĭd'ĭ-tē)

Also from Answers.com... Prostate Cancer What every man should know to protect his health.

1. The quality or state of being rigid.
2. An instance of being rigid.

noun

1. The quality or state of being stubbornly inflexible: die-hardism, grimness, implacability, implacableness, incompliance, incompliancy, inexorability, inexorableness, inflexibility, inflexibleness, intransigence, intransigency, obduracy, obdurateness, relentlessness, remorselessness, rigidness, stubbornness. See resist/yield.
2. The fact or condition of being rigorous and unsparing: austerity, hardness, harshness, rigor, rigorousness, severity, sternness, strictness, stringency, toughness. See easy/hard.

The characteristic of being nonflexible, which is essential in a connector, a reciprocal arm, or an indirect retaining unit of a removable partial denture.

That property of a material which resists a change in its physical shape.

In the context of learning, an inability to change behaviour patterns, attitudes, or body postures.

Inflexibility or stiffness.

• clasp-knife r. — increased tension in the extensor of a joint when it is passively flexed, giving way suddenly on exertion of further pressure; seen especially in upper motor neuron disease.
• cogwheel r. — tension in a muscle that gives way in little jerks when the muscle is passively stretched.
• lead-pipe r. — posture adopted when the rigidity of the limb is maintained equally throughout the passive flexion.
• r. reflex — the state of immobility generated in female animals, especially those in estrus, when they make physical contact with a male.