emotion vs zest

emotion

noun
  • A person's internal state of being and involuntary physiological response to an object or a situation, based on or tied to physical state and sensory data. 

  • A reaction by a non-human organism with behavioral and physiological elements similar to a person's response. 

zest

verb
  • To scrape the zest from a fruit. 

  • To make more zesty. 

noun
  • The outer skin of a citrus fruit, used as a flavouring or garnish. 

  • General vibrance of flavour. 

  • Enthusiasm; keen enjoyment; relish; gusto. 

  • The woody, thick skin enclosing the kernel of a walnut. 

How often have the words emotion and zest occurred in a corpus of books? (source: Google Ngram Viewer )