jawbreaking

42 Moby Thesaurus words for "jawbreaking":
      Herculean, abstruse, arduous, brutal, complex, critical, delicate,
      demanding, difficile, difficult, exacting, formidable, hairy, hard,
      hard-earned, hard-fought, intricate, knotted, knotty, laborious,
      mean, no picnic, not easy, operose, polysyllabic, rigorous, rough,
      rugged, sesquipedal, sesquipedalian, set with thorns, severe,
      spiny, steep, strenuous, thorny, ticklish, toilsome, tough, tricky,
      uphill, wicked