irritation

n. act of irritating; state of being irritated; something which annoys or aggravates; inflammation, excessive sensitivity (Medicine)

Irritation, in biology and physiology, is a state of inflammation or painful reaction to allergy or cell-lining damage. A stimulus or agent which induces the state of irritation is an irritant. Irritants are typically thought of as chemical agents (for example phenol and capsaicin) but mechanical, thermal (heat) and radiative stimuli (for example ultraviolet light or ionising radiations) can also cause irritation.
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Irritation /ir·ri·ta·tion/ 1. the act of stimulating. 2. a state of overexcitation and undue sensitivity.ir´ritative ir·ri·ta·tion n. 1. [more]Irritation - Community and Resources

Noun
1. the psychological state of being irritated or annoyed
(synonym) annoyance, vexation, botheration
(hypernym) psychological state, mental state
(hyponym) bummer
(derivation) annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devil
2. a sudden outburst of anger; "his temper sparked like damp firewood"
(synonym) pique, temper
(hypernym) annoyance, chafe, vexation
(derivation) annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devil
3. (pathology) abnormal sensitivity to stimulation; "any food produced irritation of the stomach"
(hypernym) abnormality, abnormalcy, abnormal condition
(derivation) irritate
(classification) pathology
4. the neural or electrical arousal of an organ or muscle or gland
(synonym) excitation, innervation
(hypernym) arousal
(derivation) irritate
5. an uncomfortable feeling in some part of the body
(synonym) discomfort, soreness
(hypernym) suffering, hurt
(derivation) irritate
6. unfriendly behavior that causes anger or resentment
(synonym) aggravation, provocation
(hypernym) aggression
(hyponym) aggro
(derivation) annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devil
7. the act of troubling or annoying someone
(synonym) annoyance, annoying, vexation
(hypernym) mistreatment
(hyponym) exasperation
(derivation) annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devil

n. irritation, act of irritating; state of being irritated