irritate vs annoy

irritate and annoy both are verbs.

Word	Noun	Adjective	Verb	Adverb
irritate	No	No	Yes	No
annoy	No	No	Yes	No

As verbs, irritate and annoy are synonyms defined as:

irritate and annoy: cause annoyance in; disturb, especially by minor irritations

Other synonyms of irritate include bother, chafe, devil, get at, get to, gravel, nark, nettle, rag, rile, vex.

irritate (verb)	annoy (verb)
excite to an abnormal condition, or chafe or inflame	cause annoyance in; disturb, especially by minor irritations
excite to some characteristic action or condition, such as motion, contraction, or nervous impulse, by the application of a stimulus
cause annoyance in; disturb, especially by minor irritations