What does "irritable" mean?

Irritable: Very susceptible of anger or passion; easily inflamed or exasperated; as, an irritable temper. Vicious, old, and irritable. Tennyson.

Additional senses

  1. 2.(Physiol.) Endowed with irritability; susceptible of irritation; capable of being excited to action by the application of certain stimuli.
  2. 3.(Med.) Susceptible of irritation; unduly sensitive to irritants or stimuli. See Irritation, n., 3.

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