irritability

noun

1. (countable, uncountable)The state or quality of being irritable; quick excitability.

   “irritability of temper”

   “Blue No. 1 and yellow No. 6 may also be toxic to some human cells. And as little as 1 milligram of yellow dye No. 5 may cause irritability, restlessness and sleep disturbances for sensitive children.”

2. (countable, uncountable)A natural susceptibility, characteristic of all living organisms, tissues, and cells, to the influence of certain stimuli, response being manifested in a variety of ways.

   “We find a renitency in ourselves to ascribe life and irritability to the cold and motionless fibres of plants.”

   “There is growth only in plants; but there is irritability, or, a better word, instinctivity, in insects.”

3. (countable, uncountable)A condition of morbid excitability of an organ or part of the body; undue susceptibility to the influence of stimuli.