retain vs set aside

retain

verb
  • To keep in possession or use. 

  • To employ by paying a retainer. 

  • To hold back (a pupil) instead of allowing them to advance to the next class or year. 

  • To keep in one's pay or service. 

  • To hold secure. 

set aside

verb
  • To separate and reserve something for a specific purpose. 

  • To disagree with something and reject or overturn it. 

  • To declare something invalid or null and void. 

  • To leave out of account; to omit or neglect. 

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