Synonyms For "Hardest" :
1 syllable:
firm, rough, set, shrewd, strong, surd, tall, tight, tough, vexed
2 syllables:
al dente, awkward, baffling, catchy, erect, firmly, fractious, gruelling, hardened, hardly, heavy, hornlike, horny, knockout, knotty, nasty, petrous, rocklike, rocky, rugged, scheming, severe, solid, steely, sticky, stony, thorny, toilsome, touchy, tricky, trying, tumid, unvoiced, voiceless, woody
3 syllables:
ambitious, arduous, backbreaking, challenging, conniving, corneous, delicate, demanding, difficult, effortful, elusive, granitic, grueling, heavily, merciless, operose, punishing, semihard, serious, severely, stonelike, ticklish, troublesome, unyielding
4 syllables:
adamantine, calculating, calculative, concentrated, embarrassing, granitelike, herculean, insensitive, intemperate, laborious, problematic, unmerciful