The Collaborative International Dictionary of English v.0.48:

Crucifix \Cru"ci*fix\ (kr?"s?-f?ks), n.; pl. Crucifixes (-?z).
   [F. crucifix or LL. crucifixum, fr. L. crux, crucis, cross +
   figere, fixum, to fix. See Cross, and Fix, and cf.
   Crucify.]
   1. A representation in art of the figure of Christ upon the
      cross; esp., the sculptured figure affixed to a real cross
      of wood, ivory, metal, or the like, used by the Roman
      Catholics in their devotions.
      [1913 Webster]

            The cross, too, by degrees, become the crucifix.
                                                  --Milman.
      [1913 Webster]

            And kissing oft her crucifix,
            Unto the block she drew.              --Warner.
      [1913 Webster]

   2. The cross or religion of Christ. [R.] --Jer. Taylor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

crucifix
    n 1: representation of the cross on which Jesus died [syn:
         crucifix, rood, rood-tree]
    2: a gymnastic exercise performed on the rings when the gymnast
       supports himself with both arms extended horizontally

Moby Thesaurus II by Grady Ward, 1.0:

107 Moby Thesaurus words for "crucifix":
   Agnus Dei, Calvary cross, Christogram, Greek cross, Holy Grail,
   Host, Jerusalem cross, Latin cross, Maltese cross, Pieta,
   Russian cross, Sanctus bell, Sangraal, T, X, ankh, ark, asperger,
   asperges, aspergillum, avellan cross, bambino, beadroll, beads,
   candle, censer, chaplet, chi, chi-rho, christcross, ciborium,
   crisscross, cross, cross ancre, cross botonee, cross bourdonee,
   cross fitche, cross fleury, cross formee, cross fourchee,
   cross grignolee, cross moline, cross of Cleves, cross of Lorraine,
   cross patee, cross recercelee, cross-crosslet, crossbones,
   crosslet, cruciform, cruet, crux, crux ansata, crux capitata,
   crux decussata, crux gammata, crux immissa, crux ordinaria, dagger,
   eucharistial, ex, exing, fork cross, gammadion, holy cross,
   holy water, holy-water sprinkler, icon, incensory, inverted cross,
   long cross, matzo, menorah, mezuzah, mikvah, monstrance,
   osculatory, ostensorium, papal cross, paschal candle, pax,
   pectoral cross, phylacteries, potent cross, prayer shawl,
   prayer wheel, pyx, relics, rood, rosary, sacramental,
   sacred relics, sacring bell, saltire, shofar, sukkah, swastika,
   tabernacle, tallith, tau, thurible, trefled cross, urceole,
   veronica, vigil light, voided cross, votive candle