on dit vs tittle-tattle

on dit

noun
  • A flying report; rumour. 

tittle-tattle

noun
  • petty, idle gossip. 

  • An idle, trifling talker; a gossip. 

verb
  • To engage in such gossip. 

  • To spread gossip. 

How often have the words on dit and tittle-tattle occurred in a corpus of books? (source: Google Ngram Viewer )