irritate

v. annoy, bother, aggravate, anger; cause inflammation or extreme 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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Verb
1. cause annoyance in; disturb, especially by minor irritations; "Mosquitoes buzzing in my ear really bothers me"; "It irritates me that she never closes the door after she leaves"
(synonym) annoy, rag, get to, bother, get at, rile, nark, nettle, gravel, vex, chafe, devil
(hypernym) displease
(hyponym) get, get under one's skin
(verb-group) chafe
(derivation) irritation, annoyance, vexation, botheration
2. excite to an abnormal condition, of chafe or inflame; "Aspirin irritates my stomach"
(antonym) soothe
(hypernym) worsen, aggravate, exacerbate, exasperate
(hyponym) chafe, gall, fret
(derivation) irritation
3. excite to some characteristic action or condition, such as motion, contraction, or nervous impulse, by the application of a stimulus; "irritate the glands of a leaf"
(hypernym) stimulate, excite
(hyponym) pinch, vellicate
(derivation) excitation, innervation, irritation
(classification) physiology

v. irritate, provoke, vex, nettle, chafe, annoy, gall, rile, rouse, tease, enrage, anger, fret

adj. annoyed, angry, irritated, vexed, exasperated

v. irritate, anger, exasperate; excite

v. get irritated, be irritated