giggle vs giggling

giggle

noun
  • A high-pitched, silly laugh. 

  • Fun; an amusing episode. 

verb
  • To laugh gently in a playful, nervous, or affected manner. 

giggling

noun
  • The act of producing giggles; high-pitched laughter 

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