| n. | 1. | |
| 1. | The state or quality of being irritable; quick excitability; petulance; fretfulness; | |
| 2. | (Physiol.) 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, - as that quality in plants by which they exhibit motion under suitable stimulation; esp., the property which living muscle possesses, of responding either to a direct stimulus of its substance, or to the stimulating influence of its nerve fibers, the response being indicated by a change of form, or contraction; contractility. | |
| 3. | (Med.) A condition of morbid excitability of an organ or part of the body; undue susceptibility to the influence of stimuli. See Irritation, |
| Noun | 1. | irritability - an irritable petulant feeling |
| 2. | irritability - excessive sensitivity of an organ or body part Synonyms: excitability | |
| 3. | irritability - a disposition to exhibit uncontrolled anger; "his temper was well known to all his employees" |