centralize vs relinquish

centralize

verb
  • To move power to a single, central authority 

  • To move things physically towards the centre; to consolidate or concentrate 

relinquish

verb
  • 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. 

  • To accept to give up, withdraw etc. 

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