Merriam-Webster Collegiate Dictionary - irritate

 verb  (-tated; -tating)  Etymology: Latin irritatus, past participle of irritare  Date: 1598  transitive verb  1. to provoke impatience, anger, or displeasure in ; annoy  2. to induce irritability in or of  intransitive verb to cause or induce displeasure or irritation  • irritatingly adverb Synonyms:  ~, exasperate, nettle, provoke, rile, peeve mean to excite a feeling of anger or annoyance. ~ implies an often gradual arousing of angry feelings that may range from mere impatience to rage constant nagging that ~d me greatly. exasperate suggests galling annoyance and the arousing of extreme impatience his exasperating habit of putting off needed decisions. nettle suggests a sharp but passing annoyance or stinging your pompous attitude nettled several people. provoke implies an arousing of strong annoyance that may excite to action remarks made solely to provoke her. rile implies inducing an angry or resentful agitation the new work schedules riled the employees. peeve suggests arousing fretful often petty or querulous irritation a toddler peeved at being refused a cookie.