(figurative) a course of action that is unproductive and offers no hope of improvement; "all the clues led the police into blind alleys"; "so far every road that we've been down has turned out to be a blind alley"
excite to an abnormal condition, of chafe or inflame; "Aspirin irritates my stomach"
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"