gibber vs yabber

gibber

verb
  • To jabber, talk rapidly and unintelligibly or incoherently. 

noun
  • Gibberish, unintelligible speech. 

  • A balky horse. 

  • A stone or rock, of chalcedony or similar mineral, found strewn over arid regions of inland Australia; a gibber stone. 

yabber

verb
  • To talk, jabber. 

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