floppy vs lethargic

floppy

adj
  • Limp, not hard, firm, or rigid; flexible. 

noun
  • A comic book. 

  • An insurgent in the Rhodesian Bush War, called as such for the way they "flop" when shot. 

lethargic

adj
  • sluggish, slow 

  • indifferent, apathetic 

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