What is "to grease the palm of"

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.

   Clench'd her fingers till they bit the palm.
   --Tennyson.

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.

   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.

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.

4. (Zo["o]l.) 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.

5. (Naut.) The flat inner face of an anchor fluke.

   to grease the palm of, v. t. To bribe or tip. [Slang]