n.
  - great enthusiasm and energy. ▸excitement or piquancy. 
- the outer coloured part of the peel of citrus fruit, used as flavouring.
Derivative
  
    - zestful adj.
- zestfully adv.
- zestfulness n.
- zesty adj.
 
  Etymology
  C15: from Fr. zeste ‘orange or lemon peel’, of unknown origin.