The Collaborative International Dictionary of English v.0.48:

Hardy \Har"dy\, n.
   A blacksmith's fuller or chisel, having a square shank for
   insertion into a square hole in an anvil, called the hardy
   hole.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hardy \Har"dy\ (h[aum]r"d[y^]), a. [Compar. Hardier
   (-d[i^]*[~e]r); superl. Hardiest.] [F. hardi, p. p. fr. OF.
   hardir to make bold; of German origin, cf. OHG. hertan to
   harden, G. h[aum]rten. See Hard, a.]
   1. Bold; brave; stout; daring; resolute; intrepid.
      [1913 Webster]

            Hap helpeth hardy man alway.          --Chaucer.
      [1913 Webster]

   2. Confident; full of assurance; in a bad sense, morally
      hardened; shameless.
      [1913 Webster]

   3. Strong; firm; compact.
      [1913 Webster]

            [A] blast may shake in pieces his hardy fabric.
                                                  --South.
      [1913 Webster]

   4. Inured to fatigue or hardships; strong; capable of
      endurance; as, a hardy veteran; a hardy mariner.
      [1913 Webster]

   5. Able to withstand the cold of winter.
      [1913 Webster]

   Note: Plants which are hardy in Virginia may perish in New
         England. Half-hardy plants are those which are able to
         withstand mild winters or moderate frosts.
         [1913 Webster]

U.S. Gazetteer (1990):

Hardy, AR (city, FIPS 29920)
  Location: 36.32149 N, 91.48042 W
  Population (1990): 538 (357 housing units)
  Area: 6.0 sq km (land), 0.5 sq km (water)
  Zip code(s): 72542
Hardy, IA (city, FIPS 34455)
  Location: 42.81024 N, 94.05148 W
  Population (1990): 47 (26 housing units)
  Area: 1.1 sq km (land), 0.0 sq km (water)
  Zip code(s): 50545
Hardy, KY
  Zip code(s): 41531
Hardy, NE (village, FIPS 20995)
  Location: 40.01163 N, 97.92331 W
  Population (1990): 206 (93 housing units)
  Area: 1.6 sq km (land), 0.0 sq km (water)
  Zip code(s): 68943
Hardy, VA
  Zip code(s): 24101

Moby Thesaurus II by Grady Ward, 1.0:

133 Moby Thesaurus words for "hardy":
   abiding, able-bodied, age-long, aged, ancient, antique, beefy,
   bold, bold-spirited, bouncing, brave, cartilaginous, chewy,
   chivalric, chivalrous, chronic, cohesive, constant, continuing,
   coriaceous, courageous, daring, deciduous, diuturnal, doughty,
   durable, enduring, ephemeral, evergreen, fearless, fibrous, fit,
   flush, forceful, forcible, forcy, full-blooded, full-strength,
   gallant, greathearted, gristly, gutsy, gutty, hale,
   hale and hearty, half-hardy, hard, hard as nails, healthy, hearty,
   hefty, heroic, herolike, husky, immutable, intransient, intrepid,
   inveterate, iron-hard, ironhearted, knightlike, knightly, lasting,
   leatherlike, leathery, lionhearted, long-lasting, long-lived,
   long-standing, long-term, longeval, longevous, lusty, macrobiotic,
   manful, manly, mighty, nervy, obstinate, of long duration,
   of long standing, perdurable, perduring, perennial, permanent,
   perpetual, persistent, persisting, plucky, potent, powerful,
   puissant, red-blooded, remaining, resistant, robust, robustious,
   robustuous, ropy, rude, rugged, sempervirent, sinewy, soldierlike,
   soldierly, sound, stable, stalwart, staying, steadfast, steely,
   stiff, stout, stouthearted, strapping, stringy, strong,
   strong as brandy, strong as strong, strong-willed, stubborn,
   sturdy, tenacious, tough, tough as leather, unfading, untiring,
   valiant, valorous, vigorous, viscid, vital, wiry