irritability

(ĭr'ĭ-tə-bĭl'ĭ-tē)
n., pl., -ties.

1. The quality or state of being irritable; testiness or petulance.
2. Pathology. Abnormal or excessive sensitivity of a body organ or part to a stimulus.
3. Physiology. The capacity to respond to stimuli.

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The responsiveness of an organism to changes in its immediate environment.

As a technical term in biology, the triggering of responses from small stimuli, such as gentle touch. It is a defining property of living organisms — as through their 'irritability' they do not obey Newtonian mechanics — for they are active and wholly or partly autonomous, in a way that non-living objects (apart perhaps from some machines) are not.

(Published 1987)

— Richard L. Gregory

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1. ability of an organism or a specific tissue to react to the environment.
2. the state of being abnormally responsive to slight stimuli, or unduly sensitive.

• myotatic i. — the ability of a muscle to contract in response to stretching.

n

The quality of being irritable or of responding to a stimulus.

For a list of words related to irritability, see:

• Tissue, Fiber, and Integumentary System - irritability: ability to respond to stimuli, characteristic of all living tissue

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