Source : Webster's Revised Unabridged Dictionary (1913)

Thimbleful \Thim"ble*ful\, n.; pl. {Thimblefuls}.
   As much as a thimble will hold; a very small quantity.

         For a thimbleful of golf, a thimbleful of love.
                                                  --Dryden.

Source : WordNet®

thimbleful
     n : as much as a thimble will hold [syn: {thimble}]