The Collaborative International Dictionary of English v.0.48:

Relic \Rel"ic\ (r?l"?k), n. [F. relique, from L. reliquiae, pl.,
   akin to relinquere to leave behind. See Relinquish.]
   [Formerly written also relique.]
   1. That which remains; that which is left after loss or
      decay; a remaining portion; a remnant. --Chaucer. Wyclif.
      [1913 Webster]

            The relics of lost innocence.         --Kebe.
      [1913 Webster]

            The fragments, scraps, the bits and greasy relics.
                                                  --Shak.
      [1913 Webster]

   2. The body from which the soul has departed; a corpse;
      especially, the body, or some part of the body, of a
      deceased saint or martyr; -- usually in the plural when
      referring to the whole body.
      [1913 Webster]

            There are very few treasuries of relics in Italy
            that have not a tooth or a bone of this saint.
                                                  --Addison.
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            Thy relics, Rowe, to this fair urn we trust,
            And sacred place by Dryden's awful dust. --Pope.
      [1913 Webster]

   3. Hence, a memorial; anything preserved in remembrance; as,
      relics of youthful days or friendships.
      [1913 Webster]

            The pearls were spilt;
            Some lost, some stolen, some as relics kept.
                                                  --Tennyson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

relic
    n 1: an antiquity that has survived from the distant past
    2: something of sentimental value [syn: keepsake, souvenir,
       token, relic]

Moby Thesaurus II by Grady Ward, 1.0:

154 Moby Thesaurus words for "relic":
   Agnus Dei, Holy Grail, Host, Methuselah, Pieta, Sanctus bell,
   Sangraal, account, ancient manuscript, annals, antediluvian,
   antique, antiquity, archaism, ark, artifact, asperger, asperges,
   aspergillum, back number, bambino, beadroll, beads, candle,
   catalog, cave painting, censer, chaplet, chronicle, ciborium,
   commemoration, conservative, correspondence, cross, crucifix,
   cruet, dad, documentation, dodo, elder, eolith, eucharistial,
   favor, fogy, fossil, fragment, fud, fuddy-duddy, granny, has-been,
   heirloom, history, holy cross, holy water, holy-water sprinkler,
   icon, incensory, inventory, keepsake, letters, list, longhair,
   matriarch, matzo, memento, memento mori, memorabilia, memorial,
   memorials, memories, menorah, mezuzah, mezzolith, microlith,
   mid-Victorian, mikvah, monstrance, mossback, neolith, old believer,
   old crock, old dodo, old fogy, old liner, old man, old poop,
   old woman, old-timer, osculatory, ostensorium, paleolith,
   paschal candle, patriarch, pax, petrification, petrified forest,
   petrified wood, petroglyph, phylacteries, pipe roll, plateaulith,
   pop, pops, prayer shawl, prayer wheel, pyx, reactionary, record,
   recording, register, registry, regular old fogy, relics, reliquiae,
   remains, remembrance, remembrancer, reminder, remnant, roll, rolls,
   rood, rosary, roster, rota, ruin, ruins, sacramental,
   sacred relics, sacring bell, scrap, scroll, shadow, shard, shofar,
   souvenir, square, starets, sukkah, survival, tabernacle, table,
   tallith, thurible, token, token of remembrance, trace,
   traditionalist, trophy, urceole, veronica, vestige, vigil light,
   votive candle