zest


zest (http://definr.com/zest)

     n 1: vigorous and enthusiastic enjoyment [syn: gusto, relish,
           zestfulness]
     2: a tart spiciness [syn: nip, piquance, piquancy, tang,
         tanginess]
     v : make more interesting or flavorful, either in the literal or
         in a metaphorical sense; "Spice the soup"; "Spice up the
         evening by inviting a belly dancer" [syn: spice, {spice
         up}]