The Collaborative International Dictionary of English v.0.48:

Trophy \Tro"phy\, n.; pl. Trophies. [F. troph['e]e (cf. It. &
   Sp. trofeo), L. tropaeum, trophaeum, Gr. ?, strictly, a
   monument of the enemy's defeat, fr.? a turn, especially, a
   turning about of the enemy, a putting to flight or routing
   him, fr. ? to turn. See Trope.]
   1. (Gr. & Rom. Antiq.) A sign or memorial of a victory raised
      on the field of battle, or, in case of a naval victory, on
      the nearest land. Sometimes trophies were erected in the
      chief city of the conquered people.
      [1913 Webster]

   Note: A trophy consisted originally of some of the armor,
         weapons, etc., of the defeated enemy fixed to the trunk
         of a tree or to a post erected on an elevated site,
         with an inscription, and a dedication to a divinity.
         The Romans often erected their trophies in the Capitol.
         [1913 Webster]

   2. The representation of such a memorial, as on a medal; esp.
      (Arch.), an ornament representing a group of arms and
      military weapons, offensive and defensive.
      [1913 Webster]

   3. Anything taken from an enemy and preserved as a memorial
      of victory, as arms, flags, standards, etc.
      [1913 Webster]

            Around the posts hung helmets, darts, and spears,
            And captive chariots, axes, shields, and bars,
            And broken beaks of ships, the trophies of their
            wars.                                 --Dryden.
      [1913 Webster]

   4. Any evidence or memorial of victory or conquest; as, every
      redeemed soul is a trophy of grace.
      [1913 Webster]

WordNet (r) 3.0 (2006):

trophy
    n 1: an award for success in war or hunting
    2: something given as a token of victory [syn: trophy,
       prize]

Moby Thesaurus II by Grady Ward, 1.0:

119 Moby Thesaurus words for "trophy":
   Old Mug, ambition, arch, award, barrow, bays, boast, booty,
   boundary stone, brass, bust, cairn, catch, cenotaph, chaplet,
   citation, civic crown, column, commemoration, cromlech, cross,
   crown, cup, cyclolith, dearest wish, desideration, desideratum,
   desire, diamond, dolmen, favor, find, footstone, forbidden fruit,
   garland, gem, glimmering goal, godsend, gold, golden vision,
   good thing, grave, gravestone, headstone, hoarstone, honors, hope,
   inscription, jewel, keepsake, laurel, laurels, lodestone,
   loving cup, magnet, marker, mausoleum, medal, megalith, memento,
   memento mori, memorabilia, memorial, memorial arch,
   memorial column, memorial statue, memorial stone, memorials,
   memories, menhir, monolith, monument, mound, necrology, obelisk,
   obituary, palm, palms, pearl, pillar, plaque, plum, pot, pride,
   pride and joy, prize, pyramid, record, relic, reliquary,
   remembrance, remembrancer, reminder, reward, ribbon,
   rostral column, shaft, shrine, silver, silverware, souvenir,
   spoils, stela, stone, stupa, tablet, temptation, testimonial,
   token, token of remembrance, tomb, tombstone, tope, treasure,
   trouvaille, windfall, winner, wish, wreath