a. [ L. irritabilis: cf. F. irritable. See Irritate. ] [ 1913 Webster ]
1. Capable of being irritated. [ 1913 Webster ]
2. Very susceptible of anger or passion; easily inflamed or exasperated; as, an irritable temper. [ 1913 Webster ]
Vicious, old, and irritable. Tennyson. [ 1913 Webster ]
3. (Physiol.) Endowed with irritability; susceptible of irritation; capable of being excited to action by the application of certain stimuli. [ 1913 Webster ]
4. (Med.) Susceptible of irritation; unduly sensitive to irritants or stimuli. See Irritation, n., 3.
Syn. -- Excitable; irascible; touchy; fretful; peevish. [ 1913 Webster ]