bottle out vs quail

bottle out

verb
  • To fail to perform a promised or planned action due to lack of courage or nerve. 

quail

verb
  • To lose heart or courage; to be daunted or fearful. 

  • Of courage, faith, etc.: to slacken, to give way. 

  • To waste away; to fade, to wither. 

noun
  • The meat from this bird eaten as food. 

  • Any of various small game birds of the genera Coturnix, Anurophasis or Perdicula in the Old World family Phasianidae or of the New World family Odontophoridae. 

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