(1):
(a.) Endowed with irritability; susceptible of irritation; capable of being excited to action by the application of certain stimuli.
(2):
(a.) Susceptible of irritation; unduly sensitive to irritants or stimuli. See Irritation, n., 3.
(3):
(a.) Capable of being irriated.
(4):
(a.) Very susceptible of anger or passion; easily inflamed or exasperated; as, an irritable temper.