root about vs root out

root about

verb
  • To search for something in a similar manner. 

  • To rummage; to look for something in a somewhat aimless fashion. 

  • To forage by poking the snout here and there. 

root out

verb
  • To search for and discover. 

  • To remove or abolish completely. 

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