titillate vs whet

titillate

verb
  • To stimulate or excite sensually 

whet

verb
  • To stimulate or make more keen. 

  • To hone or rub on with some substance, as a piece of stone, for the purpose of sharpening – see whetstone. 

noun
  • The act of whetting something. 

  • That which whets or sharpens; especially, an appetizer. 

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