mystifies, frustrates, irks, astonishes, confounds, perplexes, infuriates, angers, befuddles, enrages, annoys, bewilders, fascinates, confuses, vexes, amazes, bothers, stuns, puzzling, dismays, irritates, riles, frightens, impresses, rankles, terrifies, amuses, stymies, eludes, appalls, appals, distresses, flusters, flummoxes, dumbfounds, startles, disturbs, disappoints, unnerves, galls, perturbs, horrifies, pleases, boggles, defies, embarrasses, unsettles, scares, awes, reminds, tantalizes, excites, saddens, intrigues, hinders, sickens, endears, disgusts, mesmerizes, maddening, offends, exasperates, flabbergasts, dazzles, deflates, inspires, complicates, prompts, shames, wows, slays, hurts, inexplicable, thwarts, aggravates, rattles, slams, begs, intimidates, curious, preoccupies, smacks, separates, muffles, surrounds, dooms, spurs, flays, haunts, captivates, insulates, grates, wonder, repels, behooves, astound, incomprehensible, blames, stifles, displeases, overpowers, assures, baffle, diaphragms, vanes, nozzles, racks, spacers, stiffeners, struts, casings, lugs, pulleys, battens, bulkheads, coils, louvers, braces, cylinders, electrodes, flanges

closed book, enigma, mystery, secret