Source : Webster's Revised Unabridged Dictionary (1913)

Thimble \Thim"ble\, n. [OE. thimbil, AS. ??mel, fr. ??ma a
   thumb. [root]56. See {Thumb}.]
   1. A kind of cap or cover, or sometimes a broad ring, for the
      end of the finger, used in sewing to protect the finger
      when pushing the needle through the material. It is
      usually made of metal, and has upon the outer surface
      numerous small pits to catch the head of the needle.

   2. (Mech.) Any thimble-shaped appendage or fixure.
      Specifically:
      (a) A tubular piece, generally a strut, through which a
          bolt or pin passes.
      (b) A fixed or movable ring, tube, or lining placed in a
          hole.
      (c) A tubular cone for expanding a flue; -- called
          {ferrule} in England.

   3. (Naut.) A ring of thin metal formed with a grooved
      circumference so as to fit within an eye-spice, or the
      like, and protect it from chafing.

Source : WordNet®

thimble
     n 1: as much as a thimble will hold [syn: {thimbleful}]
     2: a small metal cap to protect the finger while sewing; can be
        used as a small container