zest

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Flavor or interest; piquancy.
2. n. The outermost part of the rind of an orange, lemon, or other citrus fruit, used as flavoring.
3. n. Spirited enjoyment; gusto: "At 53 he retains all the heady zest of adolescence” ( Kenneth Tynan).
4. v. To give zest, charm, or spirit to.

Century Dictionary and Cyclopedia

1. n. The dry woody membrane covering or forming the partitions of a walnut or other nut or fruit, as an orange or a lemon.
2. n. A piece of the outer rind of an orange or lemon used as a flavoring or for preserving; also, oil squeezed from such a rind to flavor liquor, etc.
3. n. Relish imparted or afforded by anything; piquant nature or quality; agreeableness; charm; piquancy.
4. n. Keen relish or enjoyment of anything; stimulated taste or interest; hearty satisfaction; gusto.
5. To add a zest or relish to; make piquant, literally or figuratively.
6. To cut, as the peel of an orange or a lemon from top to bottom into thin slips, or to squeeze, as orange-peel, over the surface of anything.

Wiktionary

1. n. Enthusiasm.
2. n. The outer skin of a citrus fruit, used as a flavouring or garnish.
3. v. cooking To scrape the zest from a fruit
4. v. To make more zesty

GNU Webster's 1913

1. 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.
2. n. Hence, something that gives or enhances a pleasant taste, or the taste itself; an appetizer; also, keen enjoyment; relish; gusto.
3. n. obsolete The woody, thick skin inclosing the kernel of a walnut.
4. v. To cut into thin slips, as the peel of an orange, lemon, etc.; to squeeze, as peel, over the surface of anything.
5. v. To give a relish or flavor to; to heighten the taste or relish of.

WordNet 3.0

1. v. add herbs or spices to
2. n. vigorous and enthusiastic enjoyment
3. n. a tart spicy quality