maddeningEnglishOxford American Thesaurusmaddening adjective she put the remaining coins back into her purse with maddening slowness: infuriating, exasperating, irritating, annoying, provoking, upsetting, vexing, irksome, unsettling, disturbing, troublesome, bothersome, vexatious, galling; informal aggravating, pestilential.