Zest

1. n. The woody, thick skin inclosing the kernel of a walnut.
2. n. A piece of orange or lemon peel, or the aromatic oil which may be squeezed from such peel, used to give flavor to liquor, etc.
3. n. Hence, something that gives or enhances a pleasant taste, or the taste itself; an appetizer; also, keen enjoyment; relish; gusto.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.