keep at bay vs parry

keep at bay

parry

noun
  • A simple defensive action designed to deflect an attack, performed with the forte of the blade. 

  • A defensive move intended to change the direction of an incoming strike to make it miss its intended target, rather than block and absorb it; and typically performed with an open hand in a downward or sideways slapping motion. 

  • A defensive or deflective action; an act of parrying. 

verb
  • To avoid, deflect, or ward off (an attack, a blow, an argument, etc.). 

How often have the words keep at bay and parry occurred in a corpus of books? (source: Google Ngram Viewer )