Definition of: zest

(zest) noun
1. Agreeable excitement and keen enjoyment of the mind accompanying exercise, mental or physical.
2. That which imparts such excitement and relish.
3. Specifically, an agreeable and piquant flavor in anything tasted, especially if added to the usual flavor, as that imparted to soups or wines by the essential oil of lemon peel, or by spice; figuratively, increase of enjoyment produced by the addition of any agreeable stimulant.
4. A piece of orange or lemon peel used to flavor anything, or the aromatic oil squeezed from it: a rare usage. See synonyms under APPETITE, RELISH.
—v.t. To give zest or relish to; make piquant. [<F zeste lemon peel (for flavoring)]
—zest′ful adjective