get rid of vs take on

get rid of

verb
  • to rid oneself of; dispose (of); to remove; to abolish; to lose 

take on

verb
  • To assume or take responsibility for. 

  • To (attempt to) dribble round (an opposition player). 

  • To catch on, do well; to become popular. 

  • To obtain the services of (a person) in exchange for remuneration; to give someone a job. 

  • To begin to have or exhibit. 

  • To attempt to fight, compete with, or engage with. 

  • To acquire, bring in, or introduce. 

  • To grieve or be concerned (about something or someone). 

How often have the words get rid of and take on occurred in a corpus of books? (source: Google Ngram Viewer )