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.
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            And kissing oft her crucifix,
            Unto the block she drew.              --Warner.
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   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