[zest] n [obs. F (now zeste), orange or lemon peel (used as flavoring)] (ca. 1674) 1: a piece of the peel or of the thin outer skin of an orange or lemon used as flavoring
2: an enjoyably exciting quality: piquancy
3: keen enjoyment: relish, gusto -- zest.ful adj -- zest.ful.ly adv -- zest.ful.ness n -- zest.less adj