erethism

noun Physiology.

1. an unusual or excessive degree of irritability or stimulation in an organ or tissue.

noun

1. physiol an abnormally high degree of irritability or sensitivity in any part of the body
2. psychiatry
   1. a personality disorder resulting from mercury poisoning
   2. an abnormal tendency to become aroused quickly, esp sexually, as the result of a verbal or psychic stimulus

n.

1. Abnormal irritability or sensitivity of an organ or body part to stimulation.