Zest is a kind of zeal or enthusiasm. If you've got a zest for something, you put your whole heart and soul into it. Dancers who have great zest leap, kick, and soar their way around the stage with a kind of joyful energy. Zest definition: keen relish; hearty enjoyment; gusto.. See examples of ZEST used in a sentence. Zesting an orange Zest[1] is a food ingredient that is prepared by scraping or cutting from the rind of unwaxed citrus fruits such as lemon, orange, citron, and lime. Zest is used to add flavor to many different types of food. In terms of fruit anatomy, the zest is obtained from the flavedo (exocarp) which is also called zest. [2] The flavedo and white pith (albedo) of a citrus fruit together makes up its peel. [3] The amounts of both flavedo and pith are variable among citrus fruits, and ... Zest of course, refers to tiny pieces of citrus rind that are used to brighten, or enhance, the flavor of food and beverages.