collect vs unfold

collect

verb
  • To infer; to conclude. 

  • To get; particularly, get from someone. 

  • To accumulate (a number of similar or related objects), particularly for a hobby or recreation. 

  • To gather together; amass. 

  • To come together in a group or mass. 

  • To collect payments. 

  • To collide with or crash into (another vehicle or obstacle). 

adv
  • With payment due from the recipient. 

adj
  • To be paid for by the recipient, as a telephone call or a shipment. 

noun
  • The prayer said before the reading of the epistle lesson, especially one found in a prayerbook, as with the Book of Common Prayer. 

unfold

verb
  • To reveal. 

  • To undo a folding. 

  • To release from a fold or pen. 

  • To turn out; to happen; to develop. 

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

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

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