amass vs stash

amass

verb
  • To collect into a mass or heap. 

  • to gather a great quantity of; to accumulate. 

  • To accumulate; to assemble. 

stash

verb
  • To hide or store away for later use. 

noun
  • Clothing or other items branded with a particular university club or society's logo. 

  • A place where drugs are stored. 

  • A collection of yarn or other materials not yet allocated to any particular craft project. 

  • mustache 

  • A collection, sometimes hidden; a reserve. 

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