backtrack vs welsh

backtrack

verb
  • To retrace one's steps. 

  • To exercise a racehorse around the racetrack in the opposite direction to that in which races are run. 

  • To taxi down an active runway in the opposite direction to that being used for takeoff. 

  • To repeat or review work already done. 

noun
  • the act of backtracking 

welsh

verb
  • To go back on one's word. 

  • To cheat or swindle someone, often by not paying a debt, especially a gambling debt. 

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