What does zest mean in cooking?

zest means: As a flavoring, grated rind from a citrus peel. (in Cooking Dictionary)

What else does zest mean?

• It is the thin and brightly-colored outer layer of citrus fruit rind. This rind is rich in volatile oils that can be used to flavor foods. (in Cooking Dictionary)
• This is the thin and fragrant outer skin of citrus fruits that can be removed using a vegetable peeler or citrus zester. It’s used for flavoring baked goods. (in Cooking Dictionary)
• Flavor and piquancy. (in Merlin Dictionary)
• Excitement or interest. (in Merlin Dictionary)
• As flavoring, the outermost portion of an orange or lemon’s rind. (in Merlin Dictionary)
• For use in flavoring or cooking, small bits of (a citrus fruit rind) can be removed. (in Merlin Dictionary)