lovesick vs mooning

lovesick

adj
  • Behaving oddly, or as though in distress, due to being overcome by feelings of love. 

  • Having an aching desire for one's beloved. 

mooning

noun
  • The act of showing one's buttocks. 

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