hard-working

from The Collaborative International Dictionary of English v.0.48

hardworking \hard"work`ing\ adj.
   1. habitually working diligently and for long hours.

   Syn: industrious, tireless, untiring.
        [WordNet 1.5]

from Moby Thesaurus II by Grady Ward, 1.0

37 Moby Thesaurus words for "hardworking":
      ardent, assiduous, diligent, drudging, energetic, fervent,
      grinding, grubbing, hard, indefatigable, industrious, laboring,
      laborious, never idle, pegging, plodding, plugging, relentless,
      sedulous, slaving, sleepless, slogging, straining, strenuous,
      striving, struggling, sweating, tireless, toiling, unflagging,
      unremitting, unsleeping, unsparing, unwearied, vehement, working,
      zealous