Definition of "thimbleful"

thimbleful

noun
plural thimblefuls or thimblesful
1. As much as a thimble will hold.
2. (by extension) A small amount of liquid, especially alcoholic spirits.
  Quotations
  “Just the tiniest thimbleful for me,” Annie said, overplaying it, I thought, since she lived on vodka.
  1988, Edmund White, chapter 4, in The Beautiful Room is Empty, New York: Vintage International, published 1994