The Collaborative International Dictionary of English v.0.48:

Crazy \Cra"zy\ (kr[=a]"z[y^]), a. [From Craze.]
   1. Characterized by weakness or feebleness; decrepit; broken;
      falling to decay; shaky; unsafe.
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            Piles of mean andcrazy houses.        --Macaulay.
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            One of great riches, but a crazy constitution.
                                                  --Addison.
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            They . . . got a crazy boat to carry them to the
            island.                               --Jeffrey.
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   2. Broken, weakened, or dissordered in intellect; shattered;
      demented; deranged.
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            Over moist and crazy brains.          --Hudibras.
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   3. Inordinately desirous; foolishly eager. [Colloq.]
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            The girls were crazy to be introduced to him. --R.
                                                  B. Kimball.
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   Crazy bone, the bony projection at the end of the elbow
      (olecranon), behind which passes the ulnar nerve; -- so
      called on account of the curiously painful tingling felt,
      when, in a particular position, it receives a blow; --
      called also funny bone.

   Crazy quilt, a bedquilt made of pieces of silk or other
      material of various sizes, shapes, and colors, fancifully
      stitched together without definite plan or arrangement.
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WordNet (r) 3.0 (2006):

crazy bone
    n 1: a point on the elbow where the ulnar nerve passes near the
         surface; a sharp tingling sensation results when the nerve
         is knocked against the bone; "the funny bone is not
         humerus" [syn: funny bone, crazy bone]