backflip vs overturn

backflip

verb
  • To completely reverse a policy or opinion; perform a U-turn. 

  • To perform a backflip (rotation of body). 

noun
  • An act of rotating one's body 360 degrees in the backward direction. 

  • a total reversal in policy or opinion; a volte-face, a U-turn. 

overturn

verb
  • To reverse (a decision); to overrule or rescind. 

  • To turn over, capsize or upset. 

  • To diminish the significance of a previous defeat by winning; to make a comeback from. 

  • To overthrow or destroy. 

  • Of a body of water: to undergo a limnic eruption, where dissolved gas suddenly erupts from the depths. 

noun
  • The overturning or overthrow of some institution or state of affairs; ruin. 

  • A turning over or upside-down; inversion. 

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