XXX vs lewd

XXX

adj
  • Extra strong; very high quality. 

  • Designating extreme or hardcore pornography. 

noun
  • Triple X syndrome. 

verb
  • To delete; to cross out, especially to conceal or suggest vulgar language. 

symbol
  • An indicator of hazard or poison. 

  • Traditional brewer's mark for barrels of extra strong beer—extended to other alcoholic beverages and other products having an extra strong dimension (varying from laundry soap to pornography). 

lewd

adj
  • Lascivious, sexually promiscuous, rude. 

verb
  • To express lust; to behave in a lewd manner. 

noun
  • A sexually suggestive image, particularly one which does not involve full nudity. 

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