WordNet (r) 3.0 (2006):

rat race
    n 1: an exhausting routine that leaves no time for relaxation

Moby Thesaurus II by Grady Ward, 1.0:

79 Moby Thesaurus words for "rat race":
   Charybdis, absurdity, aimlessness, bootlessness, busyness,
   dirty work, dizzy round, donkeywork, drudgery, eddy, employment,
   emptiness, fag, fatigue, fatuity, fecklessness, fruitlessness,
   futility, grind, gurge, gyre, handiwork, handwork, hollowness,
   impotence, inanity, industry, ineffectiveness, ineffectuality,
   inefficacy, labor, lick, lick of work, maelstrom, manual labor,
   meaninglessness, moil, nugacity, otiosity, pirouette, plenty to do,
   pointlessness, press of business, profitlessness, purposelessness,
   reel, round, scut work, slavery, spadework, spin, stroke,
   stroke of work, surge, sweat, swirl, task, the absurd,
   the rat race, tiresome work, toil, travail, treadmill, triviality,
   turn, twirl, unproductiveness, unprofitability, unprofitableness,
   valuelessness, vanity, vicious circle, vortex, wheel, whirl,
   whirlpool, whirlwind, work, worthlessness