search vs unfold

search

verb
  • To look in (a place) for something. 

  • To look thoroughly. 

noun
  • The act of searching in general. 

  • An attempt to find something. 

unfold

verb
  • To open (anything covered or closed); to lay open to view or contemplation; to bring out in all the details, or by successive development. 

  • To undo a folding. 

  • To release from a fold or pen. 

  • To turn out; to happen; to develop. 

  • To reveal. 

noun
  • In functional programming, a kind of higher-order function that is the opposite of a fold. 

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