irritation

noun

1. 1.The act of irritating or annoying
2. 2.The state of being irritated
3. 3.The act of exciting, or the condition of being excited to action, by stimulation; -- as, the condition of an organ of sense, when its nerve is affected by some external body; especially, the act of exciting muscle fibers to contraction, by artificial stimulation; as, the irritation of a motor nerve by electricity; also, the condition of a muscle and nerve, under such stimulation.
4. 4.A condition of morbid excitability or oversensitiveness of an organ or part of the body; a state in which the application of ordinary stimuli produces pain or excessive or vitiated action.