irritate

(verb) cause annoyance in; disturb, especially by minor irritations. Synonyms: annoy, rag, get to, bother, get at, rile, nark, nettle, gravel, vex, chafe, devil. Examples: "Mosquitoes buzzing in my ear really bothers me." "It irritates me that she never closes the door after she leaves."

(verb) excite to an abnormal condition, or chafe or inflame. Example: "Aspirin irritates my stomach."

(verb) excite to some characteristic action or condition, such as motion, contraction, or nervous impulse, by the application of a stimulus. Example: "Irritate the glands of a leaf."