The Collaborative International Dictionary of English v.0.48:

gutsy \gutsy\ adj.
   1. marked by courage and determination in the face of
      difficulties or danger.

   Syn: courageous, plucky.
        [WordNet 1.5]

   2. rough or plain; not sophisticated or refined; earthy.
      Opposite of sophisticated, or refined.

   Syn: earthy, lusty, robust.
        [PJC] guttae

WordNet (r) 3.0 (2006):

gutsy
    adj 1: marked by courage and determination in the face of
           difficulties or danger; robust and uninhibited; "you have
           to admire her; it was a gutsy thing to do"; "the
           gutsy...intensity of her musical involvement"-Judith
           Crist; "a gutsy red wine" [syn: gutsy, plucky] [ant:
           gutless]

Moby Thesaurus II by Grady Ward, 1.0:

82 Moby Thesaurus words for "gutsy":
   acid, beefy, biting, bold, bouncing, bulldoggish, corrosive,
   courageous, cutting, dauntless, doughty, driving, effective,
   forceful, forcible, forcy, full-blooded, full-strength, game, gamy,
   gritty, gutty, hale, hard, hard as nails, hardy, hearty, hefty,
   husky, imperative, impressive, incisive, intrepid, iron-hard,
   lusty, manful, manly, mettlesome, mighty, mordant, nervous, nervy,
   obstinate, penetrating, pertinacious, piercing, plucky, poignant,
   potent, powerful, puissant, punchy, red-blooded, resolute, robust,
   robustious, rugged, sensational, sinewed, sinewy, slashing,
   spirited, spiritful, spunky, stalwart, steely, stout, strapping,
   striking, strong, strong as brandy, strong as strong,
   strong-willed, sturdy, telling, tenacious, tough, trenchant,
   unfearful, valiant, vigorous, vital