puzzling, perplexing, mystifying, inexplicable, bizarre, bewildering, maddening, incomprehensible, disconcerting, surprising, infuriating, exasperating, startling, shocking, strange, troubling, unsettling, galling, peculiar, confusing, befuddled, irksome, laughable, unfathomable, flummoxed, unsurprising, distressing, frustrating, dumbfounding, curious, astonishing, intriguing, odd, unnerving, obtuse, nonsensical, dismaying, illogical, embarrassing, vexing, ludicrous, unexplainable, lamentable, disquieting, absurd, frightening, nauseating, ironic, disturbing, disheartening, irritating, stupefying, ridiculous, alarming, dispiriting, implausible, boggling, preposterous, weird, pathetic, inscrutable, astounding, comical, appalling, dreadful, perturbing, fascinating, annoying, worrisome, convoluted, explicable, horrid, bemused, indecipherable, discomforting, unusual, jarring, unanswerable, inapt, ghastly, uncharacteristic, saddening, noteworthy, unconvincing, depressing, scandalous, dubious, inept, counterintuitive, amusing, idiotic, paradoxical, uninteresting, unforthcoming, cryptic, interesting, unedifying, atrocious, inconsistent, boneheaded, clueless, problematic, lagging, pre, direct, provision, shielding, timbering, measuring, preparation, purification, selections, setups, tooling, avail, briefly, design, distinguishing, ex, fencing, fitting, homework, aggravating, strangest, troublesome, daunting

defy, horse latitude, mystifier, poser, protean, puzzle, puzzler, refuse, resist, sticker, stumper, teaser, toughie

difficult, hard, knotty, problematic, problematical