convey vs retain

convey

verb
  • To move (something) from one place to another. 

  • To communicate; to make known; to portray. 

  • To transfer legal rights (to). 

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. 

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