relinquish vs walk back

relinquish

verb
  • To accept to give up, withdraw etc. 

  • To give up, abandon or retire from something. To trade away. 

  • To let go (free, away), physically release. 

  • To metaphorically surrender, yield control or possession. 

walk back

verb
  • To withdraw or backpedal on a statement or promise. 

  • Used other than figuratively or idiomatically: see walk, back. 

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