The verb irritate has 3 senses (first 2 from tagged texts)
1. (3) annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devil -- (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")
2. (1) irritate -- (excite to an abnormal condition, of chafe or inflame; "Aspirin irritates my stomach")
3. irritate -- (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")