adhere vs peg down

adhere

verb
  • To be consistent or coherent; to be in accordance; to agree. 

  • To affirm a judgment. 

  • To be attached or devoted by personal union, in belief, on principle, etc. 

  • To stick fast or cleave, as a glutinous substance does; to become joined or united. 

peg down

verb
  • To identify clearly. 

  • To fasten something to the ground using pegs. 

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