The Collaborative International Dictionary of English v.0.48:

Lusty \Lust"y\, a. [Compar. Lustier; superl. Lustiest.]
   [From Lust. See Lust, and cf. Luscious.]
   [1913 Webster]
   1. Exhibiting lust or vigor; stout; strong; vigorous; robust;
      healthful; able of body.
      [1913 Webster]

            Neither would their old men, so many as were yet
            vigorous and lusty, be left at home.  --Milton.
      [1913 Webster]

   2. Beautiful; handsome; pleasant. [Obs.] --Spenser.
      [1913 Webster]

   3. Of large size; big. [Obs.] "Three lusty vessels."
      --Evelyn. Hence, sometimes, pregnant. [Obs. or Prov.]
      [1913 Webster]

   4. Lustful; lascivious. [Obs.] --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lusty
    adj 1: vigorously passionate [syn: lustful, lusty,
           concupiscent]
    2: endowed with or exhibiting great bodily or mental health; "a
       hearty glow of health" [syn: hearty, full-blooded,
       lusty, red-blooded]

Moby Thesaurus II by Grady Ward, 1.0:

133 Moby Thesaurus words for "lusty":
   active, acute, adipose, aggressive, animated, beefy, big-bellied,
   bloated, blowzy, bosomy, bouncing, brawny, brisk, burly, buxom,
   chubby, chunky, concentrated, corpulent, distended, doughty, dumpy,
   dynamic, energetic, enormous, enterprising, enthusiastic, fat,
   fattish, fleshy, flush, forceful, forcible, forcy, full,
   full of pep, full-blooded, full-bodied, full-strength, go-go,
   gross, gutsy, gutty, hale, hale and hearty, hard, hard as nails,
   hardy, healthy, hearty, heavyset, hefty, hippy, husky, immense,
   impetuous, imposing, incisive, intense, iron-hard, keen, kinetic,
   lively, living, massive, meaty, mettlesome, mighty, nervy, obese,
   obstinate, overweight, paunchy, peppy, plump, podgy, portly,
   potbellied, potent, powerful, prodigious, pudgy, puffy, puissant,
   pursy, red-blooded, robust, robustious, robustuous, roly-poly,
   rotund, rude, rugged, smacking, snappy, spanking, spirited, square,
   squat, squatty, stalwart, steely, stocky, stout, strapping,
   strenuous, strong, strong as brandy, strong as strong,
   strong-willed, sturdy, substantial, swollen, take-charge,
   take-over, thick-bodied, thickset, top-heavy, tremendous,
   trenchant, tubby, vast, vibrant, vigorous, vital, vivacious, vivid,
   well-fed, whacking, whopping, zestful, zesty, zippy