delve for vs explore

delve for

explore

verb
  • To travel somewhere in search of discovery. 

  • To be engaged exploring in any of the above senses. 

  • To examine diagnostically. 

  • To (seek) experience first hand. 

  • To seek sexual variety, to sow one's wild oats. 

  • To wander without any particular aim or purpose. 

  • To examine or investigate something systematically. 

noun
  • An exploration; a tour of a place to see what it is like. 

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