The Collaborative International Dictionary of English v.0.48:

palm \palm\ (p[aum]m), n. [OE. paume, F. paume, L. palma, Gr.
   pala`mh, akin to Skr. p[=a][.n]i hand, and E. fumble. See
   Fumble, Feel, and cf. 2d Palm.]
   1. (Anat.) The inner and somewhat concave part of the hand
      between the bases of the fingers and the wrist.
      [1913 Webster]

            Clench'd her fingers till they bit the palm.
                                                  --Tennyson.
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   2. A lineal measure equal either to the breadth of the hand
      or to its length from the wrist to the ends of the
      fingers; a hand; -- used in measuring a horse's height.
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   Note: In Greece, the palm was reckoned at three inches. The
         Romans adopted two measures of this name, the lesser
         palm of 2.91 inches, and the greater palm of 8.73
         inches. At the present day, this measure varies in the
         most arbitrary manner, being different in each country,
         and occasionally varying in the same. --Internat. Cyc.
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   3. (Sailmaking) A metallic disk, attached to a strap, and
      worn on the palm of the hand, -- used to push the needle
      through the canvas, in sewing sails, etc.
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   4. (Zool.) The broad flattened part of an antler, as of a
      full-grown fallow deer; -- so called as resembling the
      palm of the hand with its protruding fingers.
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   5. (Naut.) The flat inner face of an anchor fluke.
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   to grease the palm of, v. t. To bribe or tip. [Slang]
      [Webster 1913 Suppl.]