deepen vs excavate

deepen

verb
  • To make deep or deeper 

  • To make more sound or heavy. 

  • To become lower in tone 

  • To make darker or more intense; to darken 

  • To become deeper 

  • To become more intimate. 

  • To make lower in tone 

  • To become darker or more intense 

  • To become more thorough or extensive. 

  • To make more thorough or extensive. 

  • To become more sound or heavy. 

  • To make more intimate. 

  • To make more poignant or affecting; to increase in degree 

excavate

verb
  • To make a hole in (something); to hollow. 

  • To uncover (something) by digging. 

  • To remove part of (something) by scooping or digging it out. 

noun
  • Any member of a major grouping of unicellular eukaryotes, of the clade Excavata. 

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